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THE UNIVERSITY 
OF ILLINOIS 
LIBRARY 


QQ. 693.5 
Kee er 


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AOA UA 


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Berlin 1915. 


Sais << . 


‘Translated by N. Clifford Ricker. 


ny 
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Pt 

Lye FadeaCh LO Tanta gliilon. 

lué publication of the present tenta eaLtion ot the Guide # - 
gave bhe auLHor a renewea opportunity to wake guite extensive _ 
“ana substantial adaitions ana changes 1n tae practical as weld 
aS the tacoretical part of the HOLK, requirea by toe brogress- 
ive Gevelopment of the subject. Farticularly tne. practical os 
cortion -- Sséctions i to 1d -- has €xperiencea a very LubOr U= 


ant revision and extension, not aone for the finel feasan, at ON 


ioab just lg whe recent bike On the part of wae Opponents to. 
relulorceéd concrete so any Unjustitiably Lojurious properties 

have been attricutea to it, that in reailiy €xist nov at ali 

or merely 1o a very limitsa degree _Anotner compeiling reason | 
tor wore iuliy Geveloping tue practical portion 1s to be sougst 
in the Tact, hab LO bhe aubhor in very ouberous ‘cases, to av- : 
Qia acciacsts, 42 hore  thorougn consigeration Ons practical to 
ior construction appears wore Lmpor baat than tne. Tepe. tion ais . 4 
too extensive toecorebical comaees ae: which are ko Shaye 


LSP OL tadse acauewicagiy aus cated. “Cur ollidial eee eigtions 


also in nowlse exbema so Lar 28 Lo peewsal entirely ‘EPOSS” Paps oe 
its if tne Gonstruction;. tac rales US by stiil recelve aa essca~ 


biatly -reater sxten tl, 25 order sy ve coupsetety exnaustive 
aS & asis lor Loe sequence of ine gevalied discussions ere, 
Eglaliea the rrusslan heevlavions. Yet -- wore taan cetore: as 
4180 bus Cilicia reeuLavions of otuer lanas. have. ‘rece ivea. “the 4 
couslGeratlon aue to bnew; tor just ty the Comparative ‘ehamn- 0 4 
auiow of tnese rules, toe Stucent Teconnizes tue | ey 
1¢GS ana tue ALITLlOUL ties, Of) the wa berlais treated. eu w1to Te 
Lue present Conditions ol researca ana oe exuerieace, boere | ec ae 
are stuli suca waputola Quésiicas, tuat adil t Or an entirely as 
Gliferent conception. pue ail ogesiaeaness is: avolaca as no so 
aS pOossicle; thereiore tus educdvor 1s mace bO piace on paper. ne 
bne experlences Of Many in & saiticiently Gévallea manner. Joe 
tollowine Sections have been rewritten: -- Ah 

ili C. “soogea Horus ana #ramework” (bn1s Section was Lora— 
ériy conbalaea an Fart iL 1m condensed ror. + | 
f Yorve 1. He Viw Kersten. Kevayorcea Goncrete Constructron. 
Part Lie Applications LTO Builarnes ana Foundatrvons. 7 TA Cu 4 
VY FSeVVSEX eadVEVON. Berline ols. 

Deo: “WSads 2OP “aRlos EO WAtErVLEUU. 


Ss. “protectlon against Chemical aaa electrolytical int 


Se te ee = 


2 
loidusaces; aanger from digatoing.” 
ih. “Treatment Of visible suriaces.” 

V. “accidents and rebuilaing.” | 

Vii. “Some rules for toe graphical ee ee ot reint-— 
orcea concrete structures.” eee! ua a 

Very numerous sections are ene teal} rewrittea, ana eapecsally : 
sectiaqa Vi (Structural ana grapaical aevelopment or the vasal — | tes 
torus); X (@@lculavion or singly reinforced. q- -oeams) ; ALL EO ae 
ears ana bona Stresses); xVIL (noopea Conenete). all recent Ca ae 
aCQuisitlons 10 concrete vecunics mave founda aue consideration fa 2 f 
(steel portland cement, aadivion or slag, cast concrete, cere aes |, 
diving by caole roads, working wita comeressed alrgaa sana ibis ek 
ase, iacing concrete, tests of vealis, hooped concrete, enclos- y) 
ed cast-iron, etc.). All calculated examples nave been oenea os" 
Une and are Luralsoea wits new illustrations. — Tn tbe forbukas ©) 3 i) foie 
ana tacies for aesigning nas been euployea phe aeaie recently ey Pr 


permitted maxima Stress in steel of 1200 wl /ow*. pot. tne» 252 Rae es 
text lilustravions, i74 are ‘eatirely new, thus: only 30 cuts LD eee 
tne Tormer edition dave ceeo revainea.’ ginaliy, a very extena~ aoe 
ed alpaaoetical index to the contents nas now een aadea, eidoe Aes 
jast the practical part has experienced an ‘Auportant eniargen— ‘i | 
ent, tnis 1ndex must be of particular use; Dota tor iastructi- : 
on, as well as for. the work io tne office and ‘at the pulang 
Site, as also for business journeys. | | | 
In orucr tO mob increase tac exbent of the book too greatly» 
in a still greater extent than before and for toe less Libor t~ 


ant watters, siiall type as ceéa euployed. “Bikewise -- tor = 
the same reason -- various Sect1lons wita general contents nave By 
been condensed aS muca as possible. ete ie | be % 


Also for the present tents edition, sd far. as 1b correspond- 
ea to tae plan or tne work, tue later and newest COOKS On tHe. 
subject have deco ublilzea, particulariy the becanical jouraais 
) se (see be XLT), ana woe Te- 
searcnes (see pe 202), as nell &s the hanaoook Lor neinaforced 
concrete Construction, 2 na eaition, Vols. i and 2. ‘ne sour- 
ces given tor wore aavancea students have beem lacreasea ana 
extenged. ae 

ine autsor nas again endeavored to wRrte to be generally 
understood, particularly 1a regara to ali taose specialists 
and 6agineers, wao have enjoyed no lnstruction in relatorcea 


nereé Coming into conslaeratioa 


% 
CogStructlon, bub are reguirea AoW Cy tne Existing requirements © 
cl praculce to make tuemselves thorcusuiy acquainted #1bb tne) 
new tleéia oy private stucy or by we so-callea “special course? | 
{ne vooK supplies nO Exhaustive taeoretical trea twent; on toe ee ey sata 
yar OL tne Pecent official regulaticas, it wail ‘give ao latro~ ree Re 
QUCtLON 4S Sl&ply 4S pOossibie, now Compouna suruc wures, barul- Pian RIG a 
Cularly ln the dowain ot bulidings, are to ce Gesignea, bested” re ere 
ang erectéa. Lt assuges only an elementary anowleage or ‘tne oe AS ee i 
waloeabical pranches, 40a crings trom tne ‘Lasory not wach nore, ; 


wnan 1S necessary ior the treabucat of toe: practical suaneles, 
ana Tor undestanalne tue waterlai oF instruction ‘resented. j 

ALi in ail:-- the révision was eorodzn, SO ‘that. wols benbo 
€a1%100 broperiy bas Oo1y bhe otitLie ana tue arrangewent of one 


waberlai lo Coalon wltm vos Lirst e€aitilon: pulilsaca 5 years | ey 
since. ine value of the stall soox mast i caietiy COnSISU tor Pasa es 
Lhe mOSt part ln the iuciaiby Of arPangeneat ana uae “woe Bae 

1cily 4na créevity ol tne woae of presentation. pao ‘stall mee 
asseért1loa, Lnab by Lurtner incre aslne ine waterlal wouia ce ve 
lost the aavantagé of a cook for : schools, can scarcely be perme 


ea pertinent. Uns wereiy needs to reweiber, that 16 BOSE beca~ 


nical ‘scnools tor suscral lostrposicn, =~ ab 1easu =Ga¢ raliy wee 
too i1teie vise 18 ab Command, toat ALSO une Student, ray ti ay 
least part, 18 feferrea to alliea stuaies at Howe. in’sien 6 7 3 
Cass lust an accurate and thorougn treatment of the somewaae 
unaccustomed material be of special value to toe Stuaent wita 
Swali sCléutllicC Uraigins. and when a second point or vier, 3 
tor tué purpose of the school iinaliy ana sireaay & single’ chan? 
eap pampoiet. Suliices as a substibute LOD wie biresoue LAStruc- 

blog oy Lectures. pub eNen alter the ITlnal sxaiination, Une | 

Stuacat CoWes to the pracbicée, ana ne sees HlUselt always cow- 
belied to purchase an extenaca word. ln reyara U6 boese tno © 
bolnes of view, Ghe ereat advanbacé may se olléred bo the stu- 
aent,. of cecoming. accustomed tO ‘tae Le use Of 4 work in 

benagsa Ior practice and weil Known 1a tac Oullaine worla (Toe? 

G@ulac, Eart 1), woicn 1s s0w placea in the book traaé 1o tue. 
oisunee GL <Gi GOO scocres. 

F itt 4s the prociés of cur wldale technical scuoois to proviae 
ssistants for wne Specialist, to train practically isaformec 
persons also suiilcieéntly in tucory, tnab tboey are iater atle 
tO £OliOW BHE LTOETESS or the Speclaity lnaépenaentiy. skliiual 


2 

2s lnber@ediates between the Specialist on the one nand 
ana the workien oo tne obner,are justi as lmportant for the pr- 
actice of reintorcea concrete, as skilful office assistants & 
are ior tae aesigning engineer, ipe poly tecunic scnool proau- 
ces engineers, tne tecanicai scnool waxes specialists ana tore- 
men ror relntorcea concrete, wno are well traloea by practical 

xperience, and particularly tor tae. requirements ot tne busa- 
ness of concrete construction are indispensaciy aecessary. a 


LTOorewena 


in conclusion the author may express the #152, taau also tos 


teath 6d1ition in 1ts new form may fina tae Sais recognition in 


veconicai circles, sucn as was conceaea in Pica measure to une se 


éariler eG1t10n8. Wiiliaw drost & Son merit particular bhanks 

on ‘account of their Constant ana wiiline Concurresce. Since = | 

thé price of the book nas c€en Dut Siigntiy raised, ia spite 

of 1ts greater extent, tae preparabioa of so many new Lilastr- | 

ations, ana ol tue uniorescen airficulti es Leo Sabie: ay woe Wore 
AUgBSE. 1514. Lresaen. 

C. sersuen. 


DX : 


ax-lanations of tne abbreviations of tities of official reg- 
uiagtlons and journals. Be iy icvel Regulations. 


Frusse KEES. = AGeuLations for the Construction of structa— 
‘6S lo reiniorcea concrete, may 24, 1907, with GECrees. Oitic- | 
14i GGlLL1ON; tenth caltion, price G.60 mark. Die arnest & Son. — 


Uii. prins.= Urticisl principies for preparing, constructing 
ana testing rélulorcea concrete buliaines, éstabiisnea by Unl~ 
on of Societies of @erwan arcnitects ana Hagineers, and of Ger~ 
hag Goncrete Union. isc4. Price 0.40 barks VEaULsch. oot 

AuBU. negs. = mules tor prepring, Constructing and testing 


relnuiorcea concrete structures of Royal Warvenberg State Rail 


WayS~s rrice 2 marks. Conrad Witbwer. Stutteart. — 
AUSt. NEESs Te ie Or June 15, sly... on construction on 


siructures of réiniorcea concrete or taped concreteior See 
iheS, 1SSueda cy aecree OL kK. hk. Mroistry or Public Works. Pee 


Ge U.0uU Wark. Lenman & #entzei. Vienna. 


Swiss Kegs. = mules for ocuilaiags in reiniorcea conerete cele! 
baciisnhea by Swiss Coulilssion on relatorcea concrete, w1to deka! i 
planatiogs oy Pror. ¥. Scatile. June, 1905. Price igs 20 Wake aes 


t 


SNiss yabverlais iestige Lacsoratory. “iricno. . : 
Gene NEES. = General récuiations for preparing, ‘constructing 


anu testing bullaings of tawpea concrete, establisned by German 


WOLULSSION On réintorcea Concrete R508. 


appendix A. Stanaaras for sGddacsthes crusning (outage? 


On Vamppea concrete, wacoratory experiments. ‘ene 
Appenaix &. nules Tor conducting experiments ‘tor tae con- 
Structlon OL Oulialnes of tampea concrete. reas ae ee 0. 70 me 


Hark. (Hb. ornst « Son. 


vetile SOs. @ CeLilan Stanaaras for unifica BuEoly aad testing 
ot Portiana Cement and of steei Portiana cement. Lecree or nae oN 


ay A910. FrIice U.350 Mark. ii. orost «& SOn6 


/ 
NV Ce. yOurnals. 


x H. = peton x Hisen, loternatiogal organ for concrete con- 


struction, mocerm. construction and buildings. 40 parts as 
10 WarKS per yesr. 

Contrios. = Lefutscoe Sbauzeibune, @ontrabubrens on cement, 
conGrets aad relntorcea concrete. 24 supplements to D. Bb. 16 
LarkS inclouaging Ls. be, i104 numbers annually. 

Atle ce =. grmOrea Concrete, montaly on theory ana practice . 
Or €ntire concrete construction. iz parts yearly, 20 Marks. 


5 ee oes ae 


f | 

Cem. =. Cement, Contributions of centrai office for aiding 
German Fortiana @ement industry. Organ ot Union of German 
rortiana Cement pianuiactureps. 52 numbers yearly, 12 marks. 

Uiay =. vournal of tae Clay Industry, tecanical ana trade p 
journal ior brick, terra cotta, Lime, gypsul, cement, concrete 
ana aPtiliiciai stone; 156 numpers yearly; ic marks. 

GC. pauv. = Gentrai Journal of builaing otticials; 104 numbetr 
rs yearly, i> marks. 9 

parbner sée the special publications noted on p. 202.” 

wor aavancea stuay, seé in the first line woe “Handbuca far 
wisendetondau”, 2 ad Edition, publishea by WR. wrnst & Son. 

barticuiariy Vol. i. sistory of development ana theory or 
reiniorcea concrete. (iyliz). 

Vol. z. Tne ouliding waterials and their préepa- 

ratlon. 


_ 


Ne 


—- Te 


Aa ie WaTUn& AND CoARACTBRISTICS OF K@INZORCED CoNCnsila. 

axpianation of the aame:-- relatorcea Concrete 18 4 combina- 
tion of Concrete wita steel reinforceucat (roas, armer), by 
WOlCR COLD Structursl wateriais at toe Women’ Of LosalAg pro- 
auce a common statical efiect. aN ee 

ine Concrete, whose tensile resistance1s much less than its” 
coumpressiLle resistance, 1s caoieiiy euployea to receive tne ex-— 
lstiag compression forces, ana the steel is enclosea on ali 
slaeés by ime Concrete and 18 bo receive (permanently or teupo- 
rarily) tos existing téasion stresses, ana also ala) the concr— ~~ 
ete 1g recelving tle shear ana bond stressés. Holiowkie this 
laea, 1n whe Concrete member suoject to dena ibe are Lnserved 


steel roas of wostiy Foupa secbion, ana so accoraine bo. Boe 


i, a8 reouirea by the Choice OL affanecient to. receive toe” 
Torces a$Signea to toe, bo the COACrSbs weucer boen ouly Talis 


bose purpose of recelvlag tae ex1sbing COlpression | forces. | 


comeinea elfect of cota essentlaily altierent structural Le 


EfialsS 18 Expiainea Cy the tree LoOLlowlas Charecverlsiics. | 
@. botva maveriais firmiy aunere. togetner. ae 
ob. TIneir coervicienis of expansion are apbroxiuately couel. 


Ce WO russ Cai ve Torwea Oils tis cncLos Sa steel. 


#Or bRe graagaai asvelopment of ithe cement, concrete ana re- 
inforced concrete inaustries, tac following aates wer2t consi— 
aeration: -- . | os ; 
asthe y vosepo AS~aln \snEiana) received a patent ior proauciax 
ao artiiiciai syaraulic cement, the fortlana cerent. 

1550. FOUndIHE OL nOWan Celcol manulactory ol Leuce in G1 ee 


is4C. Pounaigk OL Tirst rorviana Cement waautactory in prance. | 


1545. JounSOn OLLalneG SUultaCie W1xihe proportions of clay 
and Lime. a 

i554. isé grencbian Lamoov cCullt Lirst reiniorcea concrete 
COate | 

4993- POUNQINe OT L1rst Geruan rortiana Cement wanulactory 
in Zuiicaow near Stevo. (op. Bbleipereue). 

isoi. fue Preachuan a alee received & patent for making 
relnicrcea concrete structures. | 

joos. #Hounaging of rortlaka Vewcat euler ake of Lyckernoir. 
x $00 10 awSsécurg near Biecrich-o-hnine- 

1505. bounding of Dyckerooll « WiGma4nn CO ln Usrisrune (since 


1907 a stock company). 

1507. Jaly 16. To the Frenchman Joseph Wonler was ceRenped a 
patent for making reinforced concrete vats. 

1805. Additional patent for tanks and pipes. 

E505. adaitvional patent for flat siabs. 
1373. Additional patent for briages. 

15/5. Aaditional patent for stairways. ben 

1577. Founding of“iinion of German Cement anutactoreys’, 
(since 1659 , Union of German Portland Cement Manufacturers) + 

i876. Introduction of “standaras for aniforn Supply ana tes- 
ting of Forvlana cement.” (Prussian Minister of Public. Works), 

(1910 Issue of “Seruan standards for unatorm supply and oe 

vesting of Portiana cement”). 

‘1oo4. Freytag & beldscauck in Neus badt-o-i- ( since 1892, Wayss 
& Freytag), purcaased German patent of wOnLEr. . 

141556. Publication ot first taeory Lor reiniogced concrete. Ss 
structures in Cent. ad. Bauv. (by ‘ids Koenen). | 

1895. Founding of German Comerete Ualon. ois Pathe | 

4504. Fublication of “Prussian Regulations tor ue construc 
tion olf relntorced concrete ourlaiags.” | n 

(i907. Second edition). — 


Coe 


Pete. 


crete” (tne work of the COnEX PE LOR) had arneedy commenced in 
1904). - : 


1300. Publication of frenca Repuletions 4 for reinforces conc- 


1907. arrangement of “German NS SS Retnforcea fone- | 


1905. Publication of “General Rules tor preparing, construc Ste 


ting and testing buildings or tampea concrete. 7‘ AY re 
ig0y. Publication of Swiss Regulations tor reinforced concrete, 


1910. Publication of “German Standaras tor uniform supply ae ae 


and testing of steel Portland cement.” ve 
1910. introduction of “General supply conditions of tne nen- 
pers of the German Portiand Cement. bb) ated iat tak belonging. in ae 
germany.” | 
dyii. Pabdlication of the Austrian Reguiations for reinforcea 
concrete. Neg eee | 
Note Le Pe 2. THe yearly product of thes wonufocdeny with + 
14,9000 HB. Pe machinery amounts to 2,200,000 varvels. This is 
the Breatest quantity of cement produced in Burope oy a Binge 


COMPANY « 


ny) 


Re } 
Fe Ten Pook * 
es 
Nod 


10 | 

NOS Ze Po Se TO tats Unian velong by far the most Ror tlond 
cement wonufacturers in Gerwony. The Bewbvers have bound. schen- 
Sees piace WVGR penalties tO eupply only Portvand cement. to. y 
the trade, that 1s free from av BUbteratian. The products. ne lesa 
of the wmewmoers of the Unionarg tested Gnnually ta the “Neborat- AO a 
ory of the Union at Korvshorst near Berlin in. every woy. ay age NS ae 
LPHLALH the PenDLtLes, the results of whe tests are asde kaown 
Vn the general assemdly. -- The total. production Of the Vavon- ad a 
va the yeor 19146 amounted to about 40,400, 200, verrele. oft Mee 
Vand cement. (Boch 4170 KL ner wevent). ve fies Sat Ue ne 

Note 1, Pe Se Phe existing means provlacd for. whe gokenitiel 


experiments of the Gommission amounted *0 226,000 works. eee ae 
this wos used $80,000 warks up to the end, of AGES. pu: ns ONG, 
i. Satety against fire. — ce See vert ieee ih fur TO rs War 
Yais 1s caused by tae bad conductiag power “of. wae concrete, ‘ 
tne use of steel by ltseli sitords ho sufficient ‘protection dan See 
from tire, ana even A Ost Cases fires cause entire destruct— oe pau ee 
ion in consequence ot, pecowing ‘red not ‘by tne heat. The bok 
ily loagea steel supports, whose bearing Capacity generally ‘. RA ee 
disappears at a heat of 600° to 600° Cy “producing: by its rd We eae 
pot oaly a general destruction of toe parts beneatn it, but eee ee: 


RG. 


also in ost cases tae overtarow of the adjacent ee a ae 


ei 


salvage work Snd putting out fire are naturally made mach more» 
Gifficult; all close fighting of the fire Ls made impossible SW iene ue 
on account of the danger frow fallinga Toe present rules of +. olen 
the duilaing officials therefore require a covering of the ae 
eel parts tor the purpose of obstructing bae direct effect ot ey | ets es | 
tae aeaton tae steel member. foverings or concrete, as such Ne 
are frequently in use, increase the cost. ot ouilaing ana cee Ee 
siderable weasure, Since in most cases it nerely represents ee ee 
aead welgat in statical respects. 1 an exception is foruea by aa 7 Be ee 
columns of enclosed cast iron. (See Section Meee as, he ieee rae! 
NOCS Be Po Se WVU srtieer \oses | at about 00° ¢ wore Voan Dare” of San ae 
Vie strength, already at 600° S whree-fourths, | ond | AL welts ot 
BVOUut AAQO® Ge But at 1000° © 14% isa.. already entirely ROTA 0 Ne ne 
Note 1. pe 4. Boom covering. WITH HOLLOW tives ona Lerra at ea 


a{ford no fire protectron free fron ovjections, | since NR OnSe 
neoted ond then subjected to a SLT eaN OF cove WOLET, these aon 
Vt\y break, and then can no Longer. prog tect twe steer from she 
flames. Likewise Vsoors with L-veaws having concrete panels 

t 


ii 

Lamped vetween them, out with unprotected {anges at votion, cama 
COMROT be termed feeefroof. Such constructions CONNOT ‘BRE NENG 
%O tne nawe of reinforced concrete {Voors. 

Gn the Contrapy in reinforced concrete ‘stractares the ‘enclos— 
ing concrete 15 the proper material, toat requires no turtaer 
protection from fire. It is in a higo degree capable of oifer- 
ine & Successful résistance to all injuries ‘by (SEECa Danger esi wens 
of falling 1s absolutely 1upossibic, weich results ina subst- 
antial reaquction of ail saivage work ana extenguisning ot fires. 
Tne tloors Can aiso support loads in fires greater than the S : 
jive loads. Svea extreme injuries oy fire can be limited to the 
story, where the fire broke out, by properly constructed floors 
of reintorced concrete. Otuner rooms remain #ivoout danger; @ git PY 
the combustible objects in them are not attacked cy eS fhe be 
penetration of the water into tne Story beneata is eftectavely 3 
prevented by # lineoleum,Govering a ‘Suificientiy thick basis — 
of asphalt. < Jae restoration of the work may proceed Tapialy, 
alter all parts aftfectea by fire and waver fave been tested Tor” 
Sbréggth by loading tests, and ‘have been suiticiently tried by 
“babplng wita a nammer.— A Rveo WibD THE uaprotectea CBSE iron 
Supports the extremely dangerous. ‘Sprinkling wita. cold water @ 
wiil not aifect toe reinitorced concrete injuriously. Slace oe 
formation of a crack in the conerete does not usually occur, : 
neitner 4 airect eifect of the red heat nor sprinkling tac wa- 
ter on tae steel parts does wee take place. < Many GAberlwents 
Have proved, that tne usual layer. covering the steel wath a = : 
thickness of 1 te 2 cw aiready suffices to secure tas permanen- fe 
ce of 4 reéintorcea concrete floor an an average fire. “ Them 
heat penetrates. bat little, and ln any GC&sé proauces superfic— 
lai injuries. Mut a destruction of the wnole is scarcely TO 
ce feared, even vy a COnbinulng action of tae ilawes; toils will Yak 
Oniy cause the plastering to fiake oil. Also Tacing Gonerele ; 
iS in general not advisable against tne effect of iianes and 
quenching water (sandstone is destroyed thereby). -- The meas- 
uré of saiety of reiatorced concrete wails can be placea < to 
4 biMES 4S great aS that of equaily thick brick walls; for the 
Same resistance a brick wall 36 cm woick may be replaced by e 
relniorcea concrete wall of about 1z to 15 cm. in tnaickness. 4 

WOV!? 2. OP. 4e See Burning of Besaers* Horehouse, Dresden. B 
& Be AVLL. pe HB. -- Ava. B. 19414. p. 362. 


. 
og “SS 
z - <= 
arpa 


; 2 . as, WER, ret oh AS Ws 
“e Vi Mine Ayo . A ' he pide aie FEO: 
é ; 


Note 1. Pe S.- Tn caloulations 9 ventan\bity the queeston ot he UE Ne 
Security against fire -- one considers the Vasurance premiun ao AER Ga eat 
Vs of Gu Vmportance not to be waderrrated, Waibe An. OWe case is 
Perhaps $4or 3 oO. Ge Vs tO be Faia Va preuiuus, AN As. biesimare Bi 
ci\ent Here with the use. OF reinforced ‘ooncrete werougnout to ae Vee cate ae 
Poy onby pout 1\4 to 1\2 ee coy for exanpre, | ‘that wakes for. oe 
the Larger worenouses a gt lne: of many, Vhousand monks | ee 


CXPAWSILOR of. the woter ia. “Ane concrete onanged ERC 
Note 3. Be be 1f in the plostering vt vs. Wntended 40 be ent- 
yrely fireproof (for exanpre in vaults), vhen naturally, ere 28 ui, 
prvoyed floors thicker than those mentioned B000e6 AS to — oe). en 
Note Ani Qe Be Bam Fer Tee Walls Bhs ‘Retuforcea Gonorete™. ie 

E & & A910. ‘S46. ak Woes fet Ty lh | 
Tae coe quakity of tne. structure naturally assumes: ce 
thoroughly appropriate arciltectaral construction. | Tn regera_ 
to tae slowness of transmission of ‘neat and of perlanence_of — ahs 
Po covering of the reintorcement in the fire and: in ftopetanaet Ay 
GO toe Gucnchlag water, pretereace as 10 be given ‘to. a GeMGNCEE | 7 ae | 
of limestone spalls to one of gravel, fnere is also. advisable cal Hu vey nore sae 
tae use of Cinder and pumice concrete. In any case ‘the concte- ae 
te must ne sufficiently old; if: too fresa, concrete ‘opambles. 
Furtaer valuadle is a good end connection ot tae reinforcement. 
by laboratory experiuents and fire tests (for. example ‘tae a as 
Vienoa model theatre) ben nave obtained the knowledge, that in 


relniorced concrete nas. been found a ee mavertai  tavepr— 


experiences in great ‘geabiiralyeanc Reo: particularly. tae Pe oa 


tire 10 whe cliy of Baltiworé, waere about 2500 nouses were Be eG 
destroyed, but all reinforced concrete structures were uni jas ee eal 
red. Tae same appeared in tae eartnggakes aad fires da San BF Be as ae 4 
francisco in 1908, ana in Messina in 1909. Ger amprovements. (6 (ous 

way further be employed a “sortar covering” : (Clay. 1g13.No. 52). ais 
Finally it may also be mentioned, that at tue instance of tne a 
central Union of German Cement Products and ‘Areificial Stone 
wabulactrers, grasite and concrete steps weré tested for tne 
Capacity of resistance to fire. While granite steps -~ in per-— 


13. | : : RN Eva 
perfectly aried condition, tnus not as” quarriedy* were placed POY 
id’ tae fire, taney broke into pieces after a snort time; tne Ba OD Mir ee 
concrete steps, made entirely normal and loaded with 400 kil/i eee a 
w*, remaanéd entirely uninjured. Suali injuries ‘first ‘appeared Oita si 51 
an tae upper surieéce, waen 4 suddea cooling occurred by. tae B LN: icant EA 
tull streau from a nyarant. + ‘Also Stude and Seicnel. mention | ’ eee yee 
in Goelr report on the tests of fireproot buildings made in ao ae 
berlin in 1693, wae faultiess condition of concrete steps” ea Ye ea Fe Moco 
contrast to granite steps at abouy a300° Ge ‘Ene ‘granite rep a 
all broke into pieces, woile tne cqnerete ey coula, be used ee ob Fe 
atvermards 4s wellas before. 4. © he One a8 

‘Hore hs teh Be The HOS% songerous couse « always renains. the = 


Sudden cooking with water, thot so Ae. given cases also. result 
ed nh a relatively Arian Lose wa ve saree gty ook whe Ldeen ia 
(Up to 40 pecs). 


@ HyGront. Result, the nanan tens. entirely, encoun 
eranrvte broke vate BARY ‘pleces, the » Tesistance of the A 
ced concrete was only reduced about AB BeCaige Sra Fe 
Certainly the concrete will ‘soften ab the Beat ot an aAnjuri 
ous fire (about 6g0°. C ia light tires and izoo* Cin ‘hard: are 
es)$ So taat its TEsistance to ‘Compression and ‘tenszoa are ae 
rp ea dlminisned. (See Note dep. 7). The. “sebting ot concrete 
occurs oy combination of water; if Bow ‘this water ‘be. lost. aga~ 
in Irom toe concrete by g1gh neat, buen must ocour a looséning 
of taé conesion. stiil bhe bearing strengta wiil always remain 
sulficlent, waen tne Conesion of tac wpole 1s ensured by bhe | i 
Steel protected trom tne, tire. ‘Por obtaining ‘greater: resista~ es 
nce to tire is recommended a leaner (4 ADs ap to 1 37) and a 
porous mixture With 4 igh adaition of water (on soe een een 
for the waxipum resistance, a rich, dense ana ary ‘wixture ot 
the concrete). f§est is concrete of orushed. stone with sizes Oe 
not larger than 25 mi. Tne concrete conducts: heat least wae A 
harder and a@enser it is. ni sah ats y's ee 


go 


Likewise ib was aetermined by fire Lestat shat wita a very. 
High temperature a separation of the steel from tne concrete ae aN ve 
Qld gow occur, So that tae static effect combinea of the eta 
structural materials was not disturbed. 4s, an explanation ey, | 


i4 . 

serve tae foliowing orief aéscriptioa of a fire test; two dat~— 
ticea steel girders, Visiatini systen, & days old, calculated | 
tor a live lead of 250. kti/m, span 5.0 o, heigat 24 cu, wita 
a load of 600 kil/w*, were acated by a strong wood fire to 1600° 
C, during tne fire being playea on wits cola water, then ‘cooled 
and finally leaded wita 1261 kal /aé ‘until taey broke. With a 
Loaa ot 1494 «ii/w* appeared a deflection of is ‘Bihe- Atvsr bac 
tire toe lateice girder (tous before tne loading test) showed 
neltser any cracks nor a measurabie defiection. ¢ Gece Mea B 

Note 1. pe Te Such experiments onvet ly extend OE op fas aoe 


i 


se DALTerent wethods of revaforcement. 

0. ¥OB® Suitaole ageredgate and wWAxing meenaekinel. te 

chy Reduction Of svrengtn during ond preci ERS TAG \wita rv 
vopie and slow COONEY. | ea | Somes Xe 

AVse see German Soumvesion. for Reinforces Concrete, Bea he 


“fire Tests of Reiaforcea Concrete Structures.” crew bad yailcedh Care 


& Son, BorWin. (arm. B. 191i. p. Aad). ay a foray 
Hote 2. Be To Experiments Va ‘the Lavoratory for clay Tnawate 2’ 
rVe3 Wndeos showed. o% 1000° o i reduction of reststance +0 Gou- 
pression 1% 3 Of 2290 to 75 ‘ivlon? and ‘a Lose» Of Reneibe reelet 
GHOSE OF 22.64 TO 464 ¥L\on*, Te Grur even -- for whe ‘same. tea- as 
perature -= proved a loss of average eoapressive resistance ae 
from S74 to. A “KLbVon* . Yer NT "one. takes Vato. ‘constaeration, — . 
TROL on Vagurvous teuperature of very Wiae Lesperatune “An on : 
SXPeriMmNy|ntay Vavoratory Lasts but. a. short time in most. cases, 
ond because the vad CONGUCTVOVtYy CUUses the heart to pass pery. Dee 
Slowly to the steel. According to Voter TRAY VOOR ES the MO 
Vessvle resistence of concrete exposed +o ‘Vvre Vs. veiuces ‘0 , 
Aout O44 Of Tha Ot the eeainning. | Parte yo es ke 
iven for yaults 1s now. preierably employed concrete, ee 
thenea in & proper Wanner by inserted steel bars (grilles). ay, as 
Bii cases,t resists melting temperatures better than a covering — 
entirely of steel, is proof against thermit ana any cutting = 
burger of the burglar. (See Contribs. i91Z. ps 139). soe 
Sés furtuer the assay, “Fire and bene fests of a Kelinforced 


_ 


Concrete Floor”, B & K. 1909, 6. 826 Also see tas renarkable 
statements concering fires. B &-#. 1911. p. 306, 322. (vonast~ 
6ry at Hamburg), as well as the publication of German foncrete 
Union; “Fireproot Qualities of Concrete, Reinforced Concrete, 


Steel and Wood.” 4914. Berlin. Also “Fireproot Quality of Re- 


| 


Reintorcea Concrete in tne greater fire: ear J Bd 
Hetts ii, <2o. ot the. German Committee tor a aba peat 
es Becurity Veomeomit Rust tor tne aemnforcenent. ; Ne 
Lisewise tae FRR, 


it appears tbat after tne aboxe covering iprevente: “cantare we ae : 
air,a aouble silicate 1s formed, Peaatacnn aptet tes big 
Listy, acide Ls toe ai) ss ep ulep prank 4 i 


rete (migture with suificient cag bevver: tnan ser ee 
material, * tae oluisa rollea surface is still to be dastingn 
ished alter years. “Phe mixture of ‘the Concrete must be these. 
gh, the addition of water not too. ereat, ‘since ovnerw: | 


resis taace he the concrete woula be appauced,, Tnere: 


WW Oolngd Bixed “Veh Water, exbivite o eadode: RNA RINE 
VW CONnseGuonce of the AyArOVVTVoal Spbitving | of whe Vinee (an- 
LeNs. 1OAR se Beta), Ge opposes the opraton, | that wre MONOKL= 
Gatvon Of the stack on concrete. Onky results. {rou the Foot, % i 


ged. The AVF, and thus the ACess .of oxygen V3. entirely exelu- 
BX, 


pal 


16 3 
NOus Ze Be 8. Iw awerica in wre seated of very Varge steev 
water pipes, | ‘an externa. and an internal, Coating | of Vhese with 
concrete has been appbicd wire fooa vesults. B& Be ABS. Pe 
Vi). PVkewise for. Ghimney GOODE structures, 0 concrete. eou- i 
eryag of the steer framework. Vn. the > Anvertor as a protection 
from rust hos coeew employed with sdvantages — 4 Mat 
ote 1. Qs 9. See Section li, ©, § spa Wis bee sacsa DS 
HOte By Be '@. 1% Woes been established by experiaents, Awat 
Lhe addition of Blog. (containing Aron. Oxiezy—ona oft olnders. MA Aa ahh 
Kcontaining eubpbur) - BO sotistoctory WROveSE LGR. fron vust can eae 
be obta\ned. es 8 of : ey Boy 
On oo part ¢ of tne Royal 5 Uaper Building officials: ia Manica, nae 
from , ageie bridge,. 17 ys ge ana exposed to heavy teadtie.| bes 
(City streets feicnenthitcdetveaders), were taken samples. trom toe 
bae soffits of tne arches (3 arcnes of 20 uw Span and 25 co tae 
ick at crown). Were fine grained concrete existed, tae steel et 
Was entirely free frou rust; only ‘in ‘the: coarse concrete appe> 
ared suall spots of rust, that coula poe cae rubbed ott | ‘ 
the finger. ! | eed | 
fo similerly favorable resuits came Nayss & , Freytag Con Tne 
had sail plECES CuL out aba eplaged anew in ei ‘seuer for use 
for ii years. The reinforcement Was: entirely tree. frou rust, ve teak oe 
Fartaerwore at toe Provincial @xn1o1tion in ‘Nurewberg. in 1506, aati tok 
a reinforced conerete arch was constructed, for whicn rusty « ha 
steel was cuployed. After tae ABlose Qe: the xaidivion, about # 
one year alter its. construction, ‘tne arcn was “Loaded antil 1b 
broke. On breaking up ana cleaning, it was” then found, wnat 
tae previously very Tusty steel nad become entirely brigot, Dre 
Ronland (Stuttgart) nas. proved tais py experiments on a ‘small 
scale. Steel bars Goated. wito ‘iron oxide, after being long, an 
Contact. with sévbing and hardened cement, were ‘broken: gut. ot. 
this ‘Tree. from rust. Bre: Robland conjectured, baat tals cond~ 
ibion was based on toe effect of tne hydraulic lime aydrate S 
Meparated during bhe setting, on tne iron oxide. + fae process” 
or removal ‘Of rust was aided by tas gypsuan contained in be Cc) 
cémeate [ae retovel o of rust occurred on all parts: of tae steel, 
that were in the oenens Contactiin sue CeMenb. 
Korte Le Pe 10. Soe Rowland; “SRewowal of Rust fron Steel AN 
Revaforced doncrete.” Svawv & BYsene. 1909, No. At. Further ane Wee 
GONVEVPS. AVBLL. P. 14d. Herts. of Socrverty of German Bagineers, | 


5 E m i 
en eta hy 
? 


nt 


fe 
XO. 26, Soncerning protectrvon {rom YUSt, Geo see &Z& &. 1911, 
P- 408, 304. Arm, B. 12912. 0. 200.— 
36 Capacity tor Resistance to Smoke. @ases. 

{t 1s known, that many burlding materials, like steel, stones 
containing lite and other wWateriais, are strongly attacked by 
Suoke gases on account of tne sulpouric and carbonic acias con- 
taéned therein, particularly wnoen tne Bases have 4 niga beuwper- 
aburé, MOSt InGonvenient 1s a frequent nverruption of the = 
WOrkKS, & great percentage of water content, and ereat variati-. 
Ons ol temperature of the gases of Combustion. ‘fhe fear that | 
also the concrete under the eitect of such gases. “lgnt deteri- “ 
orate, is taerefore not necessarily bo. be rejected, ‘especially 
Since Carponic acid and sulpaaric acid ‘Cannot be Counted witn 
tae vest friends of concrete. but Still any experiments and 
manitola practical experiences have broaucea tae contrary evi- 
Gencé wit@ objections. Very notable in this Tespect are the 
Gxperlueats OF the Austrian Kk. K. Soutnern hallway; saéuples 
were taken Lrom a Monier bridge i3 years old, indeed from bla- 
Ces Gally exposed to suoke gases frou Locouotives passing ben-— 
eatin. sas samples were then tested caemically, aud 1&6 was sp< 
Own, that the concrete always stelh possessed & great Sbrengta, 
and there appeared not toe least trace of permeability by wauer. 
Steel reiaforcewenat and concrete Tirwly adhered to eacn other, — 
fhe bearing members, like tue snail wire bands, were tree from 
ruSt and appeared faultiess, althouga tae ie tabla coat of cons : 
crete was only 2 to 3 cm thick. Sh 


for tae Saxon Railway AQWInistration, fron 1692 to 1901, some.) 


i4 great beating Gullaings were equlppea wits ‘Monier Suio ke ti= 


Py ha which while the engines were neated had to convey tne an~) Gy) 


Oxe Irom the locomotives to niga ‘obhimneys, ven for carrying 
off tae fire gases from tne shitns’ fires. ln tne loconotive — 
SM1t2 SHOP, -where a temperavure up to 400° c occurred, the Tes. | 
lutorcea concrete came into extensive use. Ali bipes were in 
excellent preservation attier tae lapse of. many years; 1G was 
even deteru“ined that tor a Higner temperature existed 4 great- 
er resistance of tne concrete; the covering oft the steel ahoun— . 
Lea tO Only about 2 cH. 

The ie cok aah rebuilt Portlana Genent Factory of the Bonn M1 
lalog & Foundry Co was entirely bullt of reintorced concrete, 
and auions Ober buings also ExHiblL’S 4 Peinforced concrete cn- 


18 
Chinney 60 mw bigh with a Gust chamber also built of reinforced 
concrete, inf which generally prevailed a temperature of 500° 
to 600° C. In spite of the strongest vibrations by stone crusn- 
ers, no leakage aas yet been found from tais chawoer. Tae pro- 
tecting covering of the réintorcement aere is indeed 5 cm. For 
Similar structures the smoke ducts and chambers, taere is adv— 


1secvle alse 4 coating of fireproof clay or of petroleau aspnalt; 


tee covering of the steel may tnen be tnoinner. 
4. kKaplaity ot Construction. 


The raw materials are delivered in a simple way, ang pehouted 
by workmen 1n tne snortest time. Gravel, sand and pebbles are — 


found everywhere; cement is also rapidly proaguced, and round 
rods are usual in commerce, always kept ready 1a great abunda- 
uce oy dealers. Reinforcea concrete Construction is taen eup- 


loyed 1p all cases with great advantage, waocre extensive stru- 
cbures are COMberned, that must be constructed in a relatively 


brief time. For the steel congis traction—~ especially in very — 
busy times, long delays ia aelivery from tne HODNEE ill are 
to be considered. 1 Gwslh Fa 
or apiaih cin hy economical use of Space, ‘great Benen 
Strengtn. | » 
Reinforced concrete 1s etees | not only to regular, bat also. aS 


t® ail irregular forums, There way be recalled nere on tne one 


aana theatre buildings, on tae otner restorations of ruins,+ 
‘fallen art monuments, etc. All saapes are indeed limited by 


the relatively hign cost of the fortis. ‘Art and cut shapes are 


readily produced, and also complex vaults ana stairways are 
constructed. Then also tne economically correct esbiwation 
of the peculiar: resistance of tae combined materials pornits . 
_ap Luportaat reduction of tne structural height, as well as a 


wider spacing of supports, for even wita the existence of. nea~ | 


vy loads, tne. ftioors may be of very wide Spéa aS a result of 
tacir great strengtn. The nuuber: or columns required will» 
thereby bs Teduced to @ Winimem; so that the interior gains @ 
sudstantially in visibility, the ventilation and tae ligat are 
also better. Just for the ‘rooms, which are exposed to certsin 
limitations in plan and beigat, nave tae advantages mentioned 
a peculiar importance. by the monolitaic charcater or tne wi- 
ole, especiaily by the arcnead floors 18 producea great securi- 
ty &g&lnst sidewise forces. 


pete 


‘ 
I, 


19 Fane oscar Wate CARR hoe ans Cet 
Nove 1. p. 12. Por exonple, certain parts of the. TwLES cee ib ie aN 
Revaelooré Gastle have seen ‘Supported by reinforced Concrete. Lies 
Reintorcea concrete also ‘perhits bhe | andertaking. of extended ng 
Yootings for detective foundations of structures. het Pare, 1p Re 
7 tA eQition, p. 151. ar Gat Cat Lan I> cee 
Likewise too little account is taken, ‘that tae resistence of” 
bas concrete way guit® considerably increase with age in some. ae 
conaitions. wea depend entirely too much on. the ‘known Gane Go 
ance of a cube after Z& days, and ado nob consider ‘that tas be 2 
résistance is often twice as great after the lapse of ‘sowe. rast | 
ars. Evén a@iter 15 years an increased resistance may ‘be proved. 
(Also see Section Til. #). according ta the statements of - ‘Dyck- § 
ernoit a“concrete of 1:6:16 after i0 years attained a Fesista-— | 
nce. 60 compression ot 233 kili/cu*, and a concrete of 1;6:13 in 
wae same time a resistance of 217 kil/cn*. at tne Gnesi 
Briage over the Danube, breaking experiments snowed a resista. 
Gee or concrete after 28 days of 254 kii/en?, ana. aiter as JG 
years, 520 kil/em*. It also appears autnorizea to abe ee 
‘siailer factor of safety in relaiorcea concrete, than 1s most~ 
iy prescribed by officials, -- as Professer ingesser - wigntly 
SayS -- SO UHat annually a Sreat amount ox the cost is” applica 
useleéssly, and the weans of the people are diminished, Oa the 
coatrary lg stecl structures tae safety can neitner increase eK 
nor Qiwinisa. 4 Pe ath aaa at ih 
Note 1. p. 13. The factor of réthiy'efnaptne soe es alee Me 


structures a3 a rule Vs taken Wieher Thon Va pure steer etrucm 
VWures, as particalorly shown A Pree ware Schivle. ag & ve OG tao. & 
Oe Saeys 
It V3 also to ‘ve GOnSLGered, shat vy detecting’ Ane hensive 
vesvetance of the concrete, as well as oy wae. vieia. Gounection 
oY vhe whole, the actual factor ot safety bk pasert sy >y wisher | 
than Vs abstained oy calculation, Tee eet 
4iso tae resistance of concrete to wear, woicn ate. & part 
‘in the production of cement slabs, steps, floors, ewce., is o ‘ 
entirely satisfactory, even frequently better than granite. It 
1S notable, that cements with hign tensile sbrengin are not +~ 
Well suited. #xperimenits at tne Materials Testing Laboratory 
au Cross-Lichterfelde with the grinding macnine (440 revols.) 
vave shown, that tae use of cpushed hard stone for the aries 
of the concrete is advantageous (granitoia slabs). Frequengly 


nf 


He 


20 ds 
4 aacition of iron filings to concrete has been made with ad- 
Vantses. (See Part Ii. 7 th edition. p. 95.). 
6. hesistance to Vibrations aad Shocks. 

ise vibrations of rapidly moving macnines exert no injurious 
intiusace, as fully proved by many Experiments and experience 
for years. Tne fear toat the reinforcement would be eraguaily 
ioosena@ oy such vibrations, and tne entire. structure thus de 
graagually destroyea, is unfounded. in consequence of tne ext- 
raordinary elasticity of the structural materials also the sh- 
ocks occurring in railway bridges are better received by con- 
crete arches strengtuenea by steel, taan by arches Oi any other 
Strucburai material, in spite of the great mass of concrete wm 
usea@ tO a ConSiderabie extent. Tae efiect of SHOCKS at the # 

¢laces concerned is not increased ip any particular Way, out 
"es transierread to ail parts of tne structure, so that fracture 


or crumOiing of the buildins is excluded at that place. fhere 


occurs only a wBembiing of the wacie; the diving force or the 
SLOCK 1S Exhausted in this manner, aoa nO injury to the struc- 
wate occurs. Just 48 this power of resistance to ‘Shocks of ® 
every Kind again offers a substantial advantage in a ‘lire: for 
toe Lear thab a relniorced concrete floor would be aestroyed : 
by faliing articles, parts of macaines, g00ds, 6tc., hostly | 
iacks all foundation. Por foundations of machines 18 to bec 
considered the’fact, taat tne concrete receives Shocks far pet- 
ber than brickwork with tae numerous jOlnts. ~~ Wi nally. reter- 
Gace 1s made to tos, that the compound construction Tinas ex- 
tensive use for fortifications Just On account of its great wii) 
elasticity. | | 3 | 
in the last great cartaguakes in San #Fraacisco and iiessina, 


crick buildings collapsed like gouses of Cards, while reintor~ 


cea Coucreté stractures nela firm. 2 One bere has to do with. 
aq extra@rainary stiitness of the wiole, in consequence of tae 
gonoligékic construction of all parts, ~~ floors, girders, Sup- 
roles ~~ there cén resuit no sudden destruction. The floors 
are constructea wita great rigidity, and no portion acts Sepa- 


Taveiy without atiecting the other parts. Wita such. (ereat vi- 


OTablons aS occur in earbugquakes, taney would first SaAOW cracks 
40a Llaking oi ine Plastering. But tae structare will not rali 
at once, in Spite of cracks produced, it preserves at least bl 

for a tlmé 16S Conesion, so that tae occupants aave time satf- 


41 

Sulflicient to save thenselves. : 

Note 1. pe 14. Bor exawple in Manila WK. eee. +0 earthque- 
kes}, a\\ new Varge Structures are our of reinforced concrete, © 
Aaa Ln Saw Francisca, Vt Ras been shown Vn renewed” earthquakes, 
that a break of the Sewers can be prevented (by ‘velnforcing | Shon 
WitR steel. -- Also see B & Be tora, os bose WBorthquakes Aw x 
BUNGATVG) ee he ee es ery pak e ci 

keintforced concréte forus a suitable waterzal tor considéra~_ 
bly restricting tne possipilivy of une extension of explosions. 
Tnerefore 1t particularly comes into coasideration for manatac~ 
tor1es or explosives, material roous, ordnance workshops, arm 
Le wails, prowectiag Slacs, bio. Asay concentrated pressure — ee 
is austributed by tne reiniorcement over larger Dearing srt. 
ces, than is possible in other metnods of construction, bo 

Nove 1. p. 15. Amond other examples, Vn On explosion A Brea 


Ben, the reinforced concrete {\oor Vy ing Over. the ‘vovler room, | ve 
On WHIGH Persons were Stil). ‘SVanding, | withstood whe ahigisbi se, 
Ge of the explosion. See Sontrivs, AQ12.: Be Meh ap ibaa Le. oo 
Ab the already mentioned rebuilding of a Portiand cement. er a 
utactory Tor the Bonn Mining and Foundry Coe, bhere were placed» a 
in tae second story of the mili building two stone epushers out 
in the first story two heavy ball mills. ‘foe vibrations exper-_ | 
lenced trom tae use of suca macaines” (for. ‘exalple tor running 
a ball mill is necessary acout 200. He Pe) are iO: important, a 
that accoraging to tae report of chiet enginesr Steppes Sateal ano~ 
ther structure erected elsewnere for tae same loads did note. be ee a 
oifer sufficient resistance, 80 that Laver ‘Suifiening nad to oe ee 
ce done. Hy ay een Seu ps Lo rae 
A very notable example of tne excellent resistance of fae se 
ebe vo snocks was furnished oy tae street fxa2bition briage eee 
Oullt in Diisseldorf in i902 (26 o Span, Latio of rise i: 14.5), ie une 
which in consequence of tne change ox Street in i903 haa to be Aa 
aestroyea. Tae breaking ioad was only placed on one half the eee 
CPidgeé; but even 425 tonnes aid nov produce fracture, so that eS 
uca were finally compeilea to destroy it with cneddite. es 
woe L1rst abltempt to break it resulted Lo breaking off small | 
bleces OL Concrete; oniy after continued pb. "aking olf the con~ © 
Crete wlio Growbars gad greatly reaucea the width of tae brla~ 
&€ Irom 9.0 gragually to 1.7 mw at tne breaking point, occurred 


sed ihe a eee Rk 
the final coliapse of the bridgé, and at a secona aLtemct to 


ees 


22 
Iracture 1t. That maximum loading of 425, tonnes equaiea Ta : 
bimes the live load used in the calculations: the bridge Seee<: 
lf was a tampea concrete bridge with three hinges, but was not 
strengtnened by steel reintorcement. See Kersten. Reinforced — 
Concrete priages. Part tI. 3 ra edition. be wee: ah pee 
7. Cheapness ana Duaability. — 7 

helniorced concrete structures resist alternations of “dpyness | 
apd wet (use for founaabions and hydraulic structures). By ane BE ces 
élr invention one. is piaced in cogaltion to construct ligater, Fel ne ae 
Instead of the usual peavy structural asses, anicn in cpaseds( 8, 
uénce of the perfect utiligation of whe ‘properties: of resiste= 
nce and the corresponding staller asses or ‘barlding materials 
causé a Smaller cost. Tne considerable expense for tae const- 
ruction of framework and centering -- especially for great doe) 
wes and nall structures -- is not to be denied, bat will ce 
waterially reduced by improvement ana simplification of the ae 
forms as well as by suitable instruction of the workwen. Bost ¢ 
iy experlwents in treatment and in fire, such as are requirea ~ ees 
for buildings in natural and artificial stone, are lacking for Ve 
tne compouna structures. by the construction of tne foras, eo 
cheaper production of the required materials and tamping the is 
concrete, the construction of buildings is wainly settled. oe 
The cost "ee freigot for the cement is also nov too. “higa,. since hag 
such wanutactories are distributed over all Germany. Cost ot Woe 
maintenance entirely disappears, ana one ‘must also. ‘Take into ae 
consideration, that 1n consequence of ‘tne rapid aod simple pre- 
paratioa of toe building uaterials, a considerable saving can He 
be made in working aays. Por example, a Monier vault requires 
scarcely nalf the time for its construction as a vault in any a 4 
otner woae of construction employed. . Ir éne finally considers, _ 
tnat in concrete structures a fireproof covering or a ‘special 
coating of tae otherwise exposea stesi oeags is excinaed, 4 
then wast 1b indeed appear, that tne compound construction in 
contrast to otner modes of construction, so far as it concerns ~ 
tne wore extensive problems, alse presents the aavantage of 
cheapness. An exceéftiina is inasea made by wooden ceilings, = 
that are really more cheaply built, yet leave so much to be 
aesirea in respect to nealth. 


Note 1. Pe 16-6 Steet structures, Gs well known, wust ve Para- 
Yea anew at Gefinite periods, not only Producing consideravle 


23 é 
GCOSst, But WY oles couses bd ride ciedic diay avetureances Va ‘he se 
of *Ahe rooms concerned, passage ot. te “ortage, eke. The Bri tev ae 
Tower ia Poris, {or exanple, Bust be pointed _onew each 3 ov We tig | at 
years, for this is always reauired 30, 909 baa wh Pornt,, fond ee ak Se Me oa 
each Painting costs about 30,000 marks. PES ena | 5 : 
P/? @, Toe Creation of Sanitary Rooms. Ieee ee ea Oe 
As tor tne demands of hygiene, the worpa of a teinforced 
concrete structure, particularly Lar schools. and. haspétals: a a 
to be regaraéd aS quite high. We have to do wita ar eaeneanae He ; 
uaterial entirely sate against fungus; ‘stagnation and. ary rot 
as well as tae formation of mushrooms cannot occur; just dike 
toe existence of vermin by tae lack of suitaole piding: places 
GreaL accumulation of dust is also ‘inpossible, since exposed 
ilanges of oeaus are lacking. Aer 
Y. Artistic freatwent. . 
Qné Can create buildings wita monumental effect; coverings: 
of stucco or otner materials are easily and securely abtacned 
to the concrete. Structures wipa wonuuental effect can be Cre 
eated. Ceilings of wide span present large ‘surfaces. ce effective. 
ana easily decoratea, waicn if necessary can be ‘painted in eh OF ie: 
colors like limestone. In recent biwes tae concrete (for hou ee oe 
sé facades as for interiors) 1s treated with pertect umiformity 
like graaive and sandstone with wallet and cnisel, to animate = 
boe surface or to form architectural ornamsnots, ‘anicn by 1 ‘tae Oe a 
strengta and the resistance to weabaer of the concrete are mg OC dea. 
Stly more durable than natural stone, ‘and that are. algo up tea 
50 p.c. cneaper, aécording to circumstances. I is indeed essu- 
wed, that the concrete 1s suitably mixed wlth the. use of a Seoll): ee: 
oper aggregate.(See Section Ii 5). Also like natural stone, cag, ig 
it oe protected from the weatner by Silicates and fluates. a ie 
Tne points of view of beauty and economy ao now always hara- eee 
onize nere. It was already recommended in tne preparation of. ee 
the aesign tor a ‘great stracture, that architects experiences 
in art be callea to advise; for it tae building be first workea a 
aut 1n calculation and constructiou, tae main lines ana divis- ON ae 
10n of suriaces, Gtc., tae arcnoitect is already deprived of ae Sng Mh 
the Most necessary expedients of fis artistic assistance. Wen 
Pa ic: all sham arcaltecture and all unnecessary overloading 
W1ltN Ornamental forms. Not ecomomical but rignt costly is atee 
also to provide coverings of architectural members, inasea for)? 


24 

tne reason of adapting tne structure concerned to tne forms of 
any period of taste. Tne form treatment of tne building ‘AB’ 
left to speak Tor itself; here 1s Concerned only the actual ee 
bullaing material and not substitutes or a wakespizt. Indeed ra 
toe torms pecullar to the combined construction are compelled. 
by the mechanical basis, and leave the arcaitect abundant opp: 
orbunity ror geeking a happy” solution, that combines ecaneny a " ) 
and beauty of form. Already many arcoivects migat be named, ear ae 
woo pave made known their Special concurrence in the enukieay: 
treatment of reinforced concrete structures, whetuer bridges Lm 
or buildings, anda tnep fave done rewarkable works: in combinat- 
lon with the engineer. + Bd oR ue * DOES ER lie AMR a ACS 

Nowe 1. Pe 1S. Bee further “prtistic Qreatment ot eda Die 


Goncrete Structures by B. von Recensetty. (Randvook for. aN ee eg 
orced Concrete gonstruction. VO\e 4. adavitonad), 

On making watertight, see Section att Bpa on chemical and el- 
ectrolytical infiuences and protection tro. ligntning, see Sec- 
tion Ili & i; on acciaents and rebuilding, see ‘Section ce 

In toe following, attention 1s ‘directed to. some points, mhicn 
are frequently brought forward by opponents as ‘disadvantages Nye oe 
oY reinforced concrete -- but woicn are in taemselves of SEVER irae 
lmportance, -- 1n view of previously mentioned advantages. | Hah 

it is objected vo reintorcea concrete, boat it bermius: no Pee ) 
ver Changes and additions, since 1% coucerns a wode of consir- 
uctlon, which exolbits an expressed wonolivaic cnaracter. it sa 
is aamltted, that in thls Fespect, the use of wood or steel Che he ay aie 
construction is more Convenient, since taere toe removal of cer & 
tain structural wembers as a rule proceeds just as rapidly ‘as a 
the addition of new wembers to tne éxisting structure. AS dest 
example, in railway buildings is” frequently the case that ‘one. 
must Consiasr later extensions, then as a ruie the preference | 
is given to steel. finally, toe same is éiso true of wanufac~ 
tories, where 1t cannot be stated ceforenaga, waat tne Eature: <: 
will bring. But likewise in reinforcea concrete construction 
always occur a multitude of changes, wnice are effected even © 
Be ge Siuply ana rapidiy. For example, an existing re1aforced 
concrete structure (wita slabs, giraers anda supports) permits 
tne addition of internal partitions at any time, since these 
indeed represent the tilling of tne supporting framework. ei) Se 
kewise @an aaditions be made oy Continuing the external panel- 


‘ 25 
panels in tne most rapid and simple manner.” ches 4 tae Sikevas 
of stairway wails wust for the reasons mentioned meet with no 
special aditficulties. A later insertion of beans. or alteration 


of tne floors or girders is perhaps not well’ possible: at) least 


tne cost of such changes will be disproportionately. igo. ‘Tae 


later additions of transmissioas or ‘installatioas for ligat and 


power present no difficulties, on the contrary. Sonceivable — 
and costly is tae subsequent insertion of an elevator, bac tre 
anster of a stairway, ete.,; since in such cases -- by cutting» 


openings +- the continuity of the floor is destroyed. “ tere Pk 


ally difficult is also tae later rewoval of Supports; yet. it. 
is to be considered, inat already in the designing was hte. , 
in view from tne beginning, to arrange the Lewest. ‘supports. 
possible, also the widest spans, in order ‘thereby to needuce# 
a truly manysided possibility of alterations. ain the use of, the 
interior and in its subdivision. But altaouga the ‘removal. of 
suca supports snould become necessary, then one opposed tae 
scarcely greater differences -- - aside from the ascten of deat 
as in pure steel construction” ~~ later structural alterations 


% 
+ ae \ 


ie 4 ee tgs 7 or v 
eat ey 
: ‘ 


ange els 


are always bad, and it isffinally Ao disadvantage, 4f one str~ ABE 


auCtural weterial opposes greater dit fioul sige: to the pages SE: 


ace considered than ‘another. + oA eva 5; Boe 
NOV? Le Pe 19. Bhe city wuthekng: dunineuset ms Seeekin “ 


1Qii Vesued a supplenentory order, in which Vs etated. omang eg hee is, cee 


Other Laings, “Tndrepensaobe reaosal . WOrk AS either 4o be. done 


wWLTLH 2 Previous understanding with the fire, that erected, the af G tae ce es 


structure in question, or be executed whith sat {ire POeE te 


(See Section ¥ A). ee es 


8 hi Hh ellie pes 
Likewise are considerable . ip the ies of. bie ake | i 


oval of reinforced concrete structures. As” a Tule, one is. cone 


pelled to use rams, lever shears, steel saws (betser. is the o 
oxynydrogen olowgipe for cutting througn tne. steel), ‘compressed | 
air chisels, ofysen Dlowpiges, explostves, etc. for. obher ‘st-) 


ructures to be torn down, the gain from the ola waterials: as wee 


rule exceeds tae cost of the necessary destruction. Stone and — 


orick can be usea ageing even steel suffers a relatively small 
toss and cannot fall belew the value of scrap, so that it-can 
always be sold.again at about 4/M its cost. Wood can av least 
be sold again for fuel. On the Contrary exists the fact, than 


tne destruction ofa reinforced concrete structure not only br- 


brings in notningy | bat die entails. considerable cost. Ana a se: Mk 3 cag nant 
tor rebuilding on a site, on ‘woich was a sahedotibi jos og! 
or of reintorced ‘concrete, basen uader ‘some Circumstances even 
a certain decrease in the value of we ground may be ‘gues 


Nebpediiniciaaed isd «nen reat masses: are. hock be broken oth ronemns 


\ 


pues of a speckalsee | 
“ Feats ci 


oats 


“BRewovel at Concrete. and s atafove padi wus ‘ 


We. sata goo Ber vin, i aaa 


produced tnereby. “Indeed only Lp Gpouint ase ; 


bee ase ot reintorced concrete la Epaaaseaaho2 


in its use for floors it cransaits ‘abana. to. < "particular extent ae 
One must ‘distinguisn between ‘ransmissioa ai sound Poa) gi Sagat 


spverience so far has baught, that. the. ‘eféects of RAE Sy Ca 
be Pe reinforced concrete floors’ are not greater ‘than for, ora ot 
tloors. 4s foe chief cause of the difficulty may be eegardeg © 6% 25! 
the vibration of the bard and elastic concrete, wnicn is faxea pas co 


— ‘ea 


va \ i) * AR Ne , Teno > EAN ay ae 
ying t t ¥) rs " py r 


iis 


Shay 


to tae walis. If one will not use pe aollow floor? | ‘ben, are at CE a 
recommended loose sand or fragments of -palice stone concrete. Saree Mk 
fragweats in a layer 3 to 4 cm thick, or even cork. slabs, Adeise. Bee ce 
with linoleum, etc., as a means wath a good ettest, b pepe 


f; 4 > 
S 5 se tekst 
aos: ate viet 

ats 


- " i ‘ ¥. j J : Ba Site 
‘ 4 Ms ‘ Rue: 
C v4 5 “Aa pat AY 
; f fiiee } } yy ‘ Lae Or, 
: : * t fis ly ‘ 4 “2 Fes 
ee CNS oy 4 : _* 35) og ee Ma we 
Aete t ‘ Wen due Tite Z Pa Ga 
: £ toes ye 4 Nga: 
s td) The ey rey 
a ps i Dg i. 4 
# h f z 
, 


wee 


ally resulting 1m an increase of dead » wengnt and of cost or cae 


tae floor. “Likewise taese only reduce tae: transmission of 8o~ a 
und vertically, but less so spe vibrations of continuous slab 
in a horizontal direction. Cork layers are also. ‘inserted in ee 
the wall masses. | {See Part Il. 7 ta edition, Rey 43)” oN 

Mote de Pe Zi, Por exanp le SVegwart, cients Site 
CevV\inee, Kersten, Part I, 7 wh ene Sey 


- ws t 


anit ewe. mation. “epaces ae 
fora a g008 resonant Toor. LY would ve. eurtonve, An sone eases 
40 {UWL the RovVlow spaces with acc Snes aang: peneren, ing 


a £004 : eee ge OF sound, 


sonkinne Qonstructione » rer “Bete “Se iit Seeman 

4nd finally, tae objection 1s still made. to. tlie Ge 
rete, that its structural treatment. Fequires a ‘thorough ‘know! 
edge of enginéering science, and. fartner a “severe, conscienti 
ous, frequently unpleasant supervision by building officials, Picea 
wnat one Cannot detect the mistakes wade ‘in vue reinforcement. 
alter tae placing at ‘tae concrete, ‘boat fa? ‘general “bhe. chpaenet or 
ulation of an-existing girder is said at nO drawings a ery 
are abMapd, | | sa pea By Hs ee Th 

On tormation of cracks, see Section: V5 “ad nell as) SP. Oe 


26 | oe 
SBCTLON Il. BUILDING MATERIALS. raat 
Tae most aecessary structural materials for waking congrete. 

are cement as tae binding material, sand and aggregate (gravel fi 

and crusned stone) as tne dilutinggmaterials. To tacse is ad- ee sie 

dea a definite gyantity of water, as well as tae reinforcement 
in reinforced concrete structures. he he as i Aa a ee 
PAA oh, The Cement. e OR Se et aia Cee gas tot 
For eekaforced cenerete buildings, Portland cement: ‘aluost o eR aan 
exclusively. comes ‘in consideration. “Fortland cement is @ wnyd= ee nes 
raulic cementing material with not less bnan ey parts by” Wein, ar as 
ent of lime (Ca QO) with 1 part by weigne of soluble silicic a © 9 §) 9 
acid (Si 02) + clay (Al2 U3) + iron oxide (Pez 03), made by ree (ee 
fine grinding and intimate wixing of tne rai tutte awed tienes ete 
at least to hag then grsnding: fine. agente eee 


ial Wideihare a0" + 


& San, Bervin. . md 


The new Austrian stovdards of 1944 eatoolished: An ‘generel. ae pe eM 
the same requirements ConceraVag aL) properties 8. the: Sermon eg mae eet 
standards, Substantially the sole difference ve Vo, the woke of | i Oa Bia eae. 


Baking test pieces For experiments on. strength. B& %.' 4244, 9220. ‘ Mois 
i. Manufactere and Packing of Portland ‘Cement. ee ea eg } 
lac manufacture of Portland cewent Chaeoe. behineawna to. ies | 
2 in the following: manner: -~ 
foe preparation; -- tae raw materials -~- ceebenise: ot line 
and clay -- are first: broken in a crusher or {by rolls-- then oan 
oried in draws -- for treatment in wixing macuines-— and accu~ ae 
‘ately weigned. fhen follows the m@xing of tae materials in = | ROS Fae ae ie 
accurately prescribed proportions, and next the grinding, ee Me ee 
Ine purifying of the raw materials as well as the grinding . Ra reget 
occurs at the same time, eitner by tae ary metaed (dry Se acaged! 
or by the wet method (web process). i ‘By the ‘dry ‘process as 3 
1ts name implies, it ‘1s ground perfectly ary ‘without the ass 
of water; and indeed this process mostly comes into use, ait = 
tne stone used be quite bard. The flour obtained is taen dam 
venea sligntly, made into bricks in brick presses ‘under ‘great 
pressure, and these are finally burned to clinker. | by the wet 
process the sorcalled mua produced by the use of soft Limestone 


eam 


2] | 

1S purified, Mlxed and grouna at tae same tle wlta tae addit—- 
100 of water. The paste obtainea is lea into pits, allowed to 
stand, and aiter acquiring 4 Certain stitiness, in tne form of — 
pieces of f18t size 18 ariea and finally curged. | | a 

Note ie pe 23. Generally the Cost oft mowul oo ture vy vhe ary 

process is Less than that by the wort process, The ehotce ~~ 
avy or wet process -- Vs atl maak. aeterained oy phe oyerr - 
ties of the row materrvals. . Van , eres. nchaee hei 
for wixing are best employed tne so-called machines: for Wine es 
ing wortar, taab are driven bota by hana ana wachine ‘poner, @ 
and eae work of mixing werely oy Anand in contrast wita ‘tae. aa- 
vantages of wore perfect ana better wLx1Og, atfords. a greater — 
saving of time and space. ne ae ee ERM a ae 
Tae burping process: -- the calcining oe: the dried gaterial 
ls Carried on BOW 1n the Ring or Dietz ‘kilas” an ‘stories, ‘bot. 
now wostly in rotary kilns, tnoat present the special advantage, 
baat tue cruaé stuif 1s arica and without furtaer forming into 
jumps, ourat to Clinker 1n the most reliable uanasr. (Softening 
. of the raw waterials in a white eau at about 4500° ¢). By ‘the - 
introduction ot rotary kilns bas been made evident 10 recent 


rg) 


years an increase 1n strengta ap. to 30 ‘PoC. ue ee i 
BP. Aq. 


KOte Ze Pe Bde Rotary ¥KV\as are rotating Veron. oybingers | Vanes | 
with Tire resisting warterral, they ave {ives from one. end Aottn if ut 
POuderead GOGL, Later abso with $08), while whe raw moter tal As. ae an 
Vatraduced at the other end. += On advantages: ons Fdejects: of ACTER ct 
rotary Kins, 8e2@ gontr vos. Asai. ‘gi 134. : 
On the properly chosen maximus temperature depenas: tne qual 
ity of tne cement in a Alen Gegrec. Too bign fe) vemperature, 
that would produce a Complete Tusion of tae stone, ast ‘not g 
occur, since then a so-called dead mass originates, ‘woich as 
not weil suited for further use. (In toe neat for olinkering a 
is proaucéd a mass, entirely soluble 1 muriatic. acid). a 
Tne burnaéa bricks or so-callea “cement Clinkers” are exposed” 
lor sowe time to tog 6 en air; then are reteyyy crushed in i 
coines (ball niiis)°Ree ane Pindlts seanaca 0 powder by gring~ 
ing. 4 According to the German Standards the cement wus b be so : 
tinely grounc as to leave not over 5 p.c. on a plate sieve with 
yvO noles per cut. ~ this powder is tae proper Portland cement 
and 1s “seasonea” for a time in ary and airy rools, sO as to 
acquire adhesive strengta, ana to prevent later efflorescence 


grikes oe, OE Pe 


i 
a oe: 
ut o 
ae 
‘it 


25 
or balr cracks. | : 
Note 1. pe 24. The Finest around cements arg nov sways whe 


cest., They even favor sharvakase vn rick wWixtures, and ollow | eS 


the cement to be wore ropidly Wjured Va seasoning. ‘The cement as 
S2%S Wore Quickly ond attains Less eke dle evrength, aN NOV ee, 
WVMSO, wetA sand. a i ah Mages ae i 

Wote 2. ps 24. A remainder of 95 boos As. ot Xoo ie, “hough 
WOS% Gewents Leave scarcely any residue Qn oO -20Q ove Seve. ; 

storages ln such rooms is entirely ailowable, since’ on accou- 
nt of 1ts BlgD deBsity, the cement very alowly absoros: dampnes: 
and carbonic acid from tne air. pat la tue course or ‘blue t 
iiag eraagually taouwen slowly become less aanesive. Only varia 
tious of temperature, eifect ot ligat, wind currents or ia 
ess Gan already lnjuriously afiect ae cement after aed 
seasoning. Datpness especially wakes tne cement lompy ¢ : 
soon useless, since it partiaily sets. &lso- bos seasoning pe~ 
riod must not exceed a certain time. 3 ie 


NOV] Se Poe 2a. The Royer Testing Lovoratory ae Grose-Lichter- 
{evae has Geterained, that cement Loses consideraole ‘atrengtn 
after sawsoning 6 Honths in ary ‘storehouses {ree {rem raft. oO 
_ff¥oen tirst foliows tae packing in casks and ‘sacks, es woien 
are ilkewise to be stored dry, anereby tne quality ot tae cem- 
ent 18 yet lncreasea. MOSt Common 1S the packing 10 ‘sacks Of 
50 kil gross welgnt, packing cre casks only being done tor: ra~ 
aSpOr® over sea. aA normal cask of “Portland cement of 170° ‘kil oS 
net or 150 kil gross weight contains about ees litres, and a 
sack of 50 kil about 36 litres. - Casks ana SaCks. muse Snow 
vhe weight and also tne factory brana of une furnisning busia- 
ess nouse The empty casks ana sacks are returned to tne anu 
iactory, if well preserved, ‘and are paid for in a tix sed” way ae ‘i 
\l.€. as a rule 0.50 mark per sack). Ihe sacks: (wetted) can be 
uScG W1L aavantage to cover iresnly tamped layers: of concrete, _ 

NOV? A. Pe Zhe Jude] Backs as Oo fvule, that can be used Ios ae 
10 tVwH)es. Cotton and paper sacks have proved unsuitadbes hgow ace ay seit 
ante ADLA. De BB) | eee wat 

Nove 1. Pe 25. Por cavcurlotrons, the werent of 1 ne oft. cement 
VS taken at 1400 kil. For whe OUNVGLAL Bite the cewent excep- 
VVonalby comes In a Loose condition, for which vy experVients | 
Of Burchartz, on average wereht of abourt 1200 Bir\ ne seens fixe 


2a. At Veast is ewoloyed 1800 kil\m’. 


2 Sich naa 
4il kinds of wortar, which for cheapness are wanufactured = 8t—itsé«S 
otnerwise thas in the prescribed banner, are not Portland ‘Cehi~ | | 
ents, aa in Case tasy come lato tae ‘trace in taat name, are. oe 
to be regarded as falsifications. ail additions in burning = 
are opdjectionable, especially mineral coloriag materials, that 
serve to glve the cement a better appearance. Such additions 
are aluost always wade at the expense of tne cement; only ult- 
rauarineé Torus aa exception by its hydraulic Oe ae 
Can even ce adaea in Considerable Quantities, (up to 40° Bo )e 
A small aaaition of raw gypsum (lime sulpaate containing water) 
in unburot conaition (up to Z p.c.) is also allowed, apd: indeed 
in grinding the cement. It lacreases the strengta aod for quick | 
SeLbing Cements, lengthens the tine of setting. é : ae 
Hote 2. Pe 25. If the riven addition Ot 2 waka Ne aabeeneds 


then tae Lacrecsed addvtvon of dypsum woy COUSS Soleo 
of the wortar after. ‘setting, the mortar then begins: to expand. 
Thus Gare Ve to ve taken MERC To be ovortded AS avso. Qepeue os 
CONLTAVAIARE Cement colors. % ae eae 
PAG, 2, Characteristics of Fortlaad Cement. a eas ahs 
Portland cement is a fine powder npnaeRty ' perceptible to the yes 
touca, of greenish- or. bluisa-gray color. : * Its specific grav- Re Paine a 
1ty amounts to 3.1 to 3.5 in a bard. condition, according | to a 
bit—thve-COntent ana tae ‘good. burning, baus: being: higher than , 
the specific gravity of almost all other. cementing cea 
torea cement always has @ smaller specific. ‘gravity ‘bnan freso— | 
cement. (Locsening by acsorpiion of: dampness). “According to a 
burchartz, 1ts weight is 1.0 to 1.4 kil ter litre, averaging 
1-26 kil per litre. ea . : Sak 
Kotewte ese es: ¥icroscopte BRI | ‘eases chee the youder | 


Ve entirely composed of thin and flat particles. : ua Wee 
waxed witn water * after a certain time and without any fare 

ther aadition, tae cement forms a solia body, mich becowes t 

tne harder, tne longer it is exposed to the iniluence of air ae 

or water. Toe change from the paste to the sioid condition | 

1S terméa the setting of the cement, toe time required for. this, 

(about one nour) is termed the setting period, and tae furtner aOR 
increase ln stfength 1s tae hardening process. An exact deter- 7 

llnatilon of the setting period has no great practical value. Ss 

Une then speaks of a "set”cement, ubeu no longer able to wake 

a permanent ippression cy a light pressure of tse finger nal. 


bObh procedures are uot to be Conrused W1lta eaca other; tne 


30. | Mie 
naraening process first degins woen the setting period is alr- Pe MN St Op 
eady enaed, end finds 1ts termination wita toe abtainwent of Oa a Ce La 
tae highest strengta, that only occurs alter years anaer some OE Re Fes Mog: 
Conditions. kest and protection from drying too rapidity favor | 
bos setting process in very great measure.* In the setting of 
portland cement always appears a small increase. in neoatee 

Pitat 1s greater the quicker the cement SETS. BG a cement ledger: eee 
eady set 1s mixed wlto water, it possesses little or no beet ty 
of maraening. Tueretore one tust always prepare only: so wun 
as Can Cé usea lo tne tle avarlable. | 


Bote 2. Pe Bow Hara water containing, gypsum retoras we. erin 
Lune, out Vacreases the strength. aw genera the bok iby dk g Ns i 
the greater, the Less water Vs used a wixing. i Be ae 

Note SB. pv. 26. From Cement worrtar must no% ee taken vefore- 
hand the water ROS CHE eee Tor VWs settinds. § Ar Tirsy WG ONG 
Sun wust be kept fron i, ond Gurine she {irst days. Vt wast be 
Spr inked Suy{wrently with Fresh water. oe ia 

According to tne duration of tne setting process are nate 
guilsaed quick ana slow setting cements. i {Tae latter bardens 
only after a sétting period of at least two hours, and tor Lbs. 
greater strength and safer working is decidedly to. oe Prefers 
rea bo tne quick setting cement. The latter is ‘particularly | 
employea 1n works under water pressure cornices, plastering, 
as weli as for tae magutacture of cel iyoreas concrete ‘pipes, hc es 
where Quick setting is generally necessary. Ine before erin BE 
ed adaition of gypsum nas only tne purpose oi making d oumek 05 0s" 
cement slower setting without Bajuring its Strengta. and son 
versely, one 1s able LO..give the Siow setting Cement a snorter 
setting period by mixlng 10 with warm water (in small weagnre). 
Hoaglua carcConate ana potash likewise Shorten the setting period, 
while suipaates and lime chloride < proauce a longer setting 
‘period. Likewise an exmess of water extends the setting period 
of tne cement. But aiso the actually prevailing temperature — 
of the air has a substantial influence on tne setting period; © , 
tor 10 Gry 40a warh weatnertae cement wiil Sev wore qURC KEY, cae 


than 1n damp and cold air. ) 

KOtS 1. Po ZT. AS SLOW SeTTINE VS COnBsIGered Oo Gement, If a 
Cement paste wode Trow Vt with 25 tO 380 9.6. water oegineg +o 
BevY ROL Kefore 20 wWinutes after Wiking, and requires at Least 


~ nours to 3 1\2 nours for sett\Vnd. (Austrian Regulartvons). 


Ree Neg tanhan: of the Nerdening of nornal sven). gotting ROR 
ent WUST NOT ooo wetore | one howe otter mixing. (German Bon 
Gards}.— ; tate: . ate 


soda, ‘VAG Se 
Voda ot concent. eabse re Bous, 1948. yack whit g Eee: 
For reinforcea concrete the quick setting cements: shee 
estion Latte or ROw au ail, ene ipo: fa | 


Sexhaule to the nign requirexents: bass (henge structures. “Bes 
ides: 3a quick pee: cement must. be wade very oft, A | 


the centering is. ‘not able to > place tae ateuk sevbing. pi Bea 

in a wore favorable light for reiniorceda concrete construction. Pe ae ay aa 
As for wnat concerns the strengta of Portland cement, as ai- ‘ I 

ready mentioned, this increases with the duration of tne Pe ae mg 7 SR 

ening process, bat already after a tew. aays acquires a relati- UE 

vely ign measure, if rest and protection against too rapid + x teas a 

drying during the setting. ‘period are given. Barticulariy yaaa E Rim, 

wae beginning of the time ot hardening the strengta increases ae 

gulbe rapidiy, while later. it progresses wore slowly. Ia prac- 

tice 1s employed especially tne resistance of tne material to. 

compression, since its resistance to teasion is about i/6 to. 

1/40 as muca. + Simplest -- but also least reliable -- is the — Bi 

test of tensile strength, since at requires less size and igs © 

therefore wore quickly and cheaply made. The tensile FErqae sa.) 

of the cement mixed. wita sand is. increased by finer grinding | 

of tae cement, waich. on tne » contrary 18 reéauced with pure cen 

ént. The resistance to compression ‘48 tach aetermined by tae 

above ratio of botn resistances, ‘Yet 1t will always be advisa~_ 

ble to ootain directly tne compressiie resistance of the cement 

cy special erusning tests, since the conclusions derived frow : a Ba we 

wae tensile strengta can farnisa no accurate and unobjectiona- SiMe cui 

ble results, and moreover tae crushing resistance 18 most’ aimp- Raina ees 

ortant for tae judging of cement. As arule tae average crusn- 
strengtn of standard mortar, be Cement + 3 standard sand, 

ah 26 days amounts to 250 to 350 kil/en@, and the tensile 


a 
iit 


ays 
¥ 


32 


resistance to 22 to 27. ni hon, tested according to German ate i 
andards. 3 : a Bee it ee 
Rote 4 oe ZB Aancaiah. ‘xo Gernan avanderda, the csi a are 


StVenSih Vs “ncw . -eViminoted, whereby. whe wequivemants for. erueh- 


Wag veststance of | standord mortar was. “Ancreased. After the. eer ae 
troduction of - the stondoras Oy consideraule Anoresse, ot: whe ves bia 


\etance to compression actually osourved. Pee OO aa a res 

Note 2. ps 28. The Laboratory of the Wwion of German. Sete sane 
Cement mokers in: Kor\shorst supplies: German Stondord sand ot a 
Brice of 5 works Mich tias A ‘ om ee a 


MOChine. phe: At ting of sehe sand. As done ~s euvnging. otanae? 3 
suspended: Vike o eaneeven, We One aveue As = {net taken out he i: 


Vw the | ‘Royal. esting Aahinesary An iia abayacubnae 

Por Supervising. Ake sine. Of. ‘évaing | serve steves. ane A a 
sheets 0,25 um. Kaek wth round holes Roving, voneters of oe 
and O675 wm. ed RO UN, ARG SS inant hw Hi na. 


sacked, each sack being closed: by whe wead | peak ee ANe: Royal | 

Testing Lavoratory. (Gerwon ‘standords). Pe on) 4 hl 
NOG Ae Pe B28. The Gerwan etendarde require: Ane foVLouind R he 

resistances vo crushing: me Walt er tee A ate wae 
Ge After T days in wcter, at Veast 420. waka oe ay 
bv. Af ver. aba days Vn wotem, af Veost 200. even? ABaener iy” bee 

160 wiv\ou*, AN A Plea ahaa ee BPs ae ante 
Ge After cowbined navies tien \euat 280 wlen®, a Aa 
Portland cement is essentially wore perwanent in volume Aaa 3 ‘ 

other cements, 1.e€., heat and ‘cold as well as wet and dryness. 

aifect its volume in far less measure, Thorough experiments a 

bave indeed proved, that. Portland cement is water experiences eke, 

a slignt expansion and in air 4 small sarinkags, and that these — 

two phenomena appear wore: strongly ab the beginning of the nar- 

céning, to finally entirely disappear in the course of time. 3 
but as a rule, it nas not been necessary to take into account 

Such Changes 1n volume on account of their insignificance. Yer 

if ome desires to do so, then for great wasses care bay ce tak- 


a ” 


3 : 33 
taken to make varougn Joants, taen fil 
Gic material, 
will be We cnanges 3 in volune, ‘pariag ae 


igre Hat See 
strengtn. * , ae permanence or ge Sa 


ps ete 
are, 


Oy ek Cai bi ‘ at 


it, 


fa wat 


wita ccfeotive ceuents, and tae a ae 
myn eg Cash gs of bag cee ney ore 


E 


300 Sahat aL t 
Inperfeet and unequal: waxing 


i 


foo at ten percentage ee 


wae : peseniaat) a cement. 
tae so-called hang Liao 


er cement blocks in ie anes bere : 
ent alternation of cold and aryness. Pa in pleste 
in the open air, hair cracks are bad. to pesonagprea as 
with too rich @ mixture, “It oas: also a fact, that ¢ 
ocks of wet concrete (see Ps 41) shor greater tneliatien to 
hair cracks, than taose epee Tei muschg 


A good. means: for "preventing such sn @ppearance is tae 


ey 
"2 
ia 
oo 
ae 
et 
ae 
ae 


} : bl ; 
arrangement oi blind joints ia tne plastering, wbien divide are 
the entire surface into smaller parts. Iv is also advisable we 
keep the plastered surfaces wet during tae sevbing period by 
means of wet clotas’ and spraying. One likewise bile eet i 
fresh coatings: trow sun and wind, st 


aces the eracks do not appear as. | guess 3 as. ‘on ‘smooth: ‘garlaces: 
Hair cracks are. not: ‘injuries, BO. nh Agnes as tae Materials sprodes « 


2 13 


ae Cracks are toen sheng oe 
oe ‘Testing Portland She gare 


resistance of asta after. + ee in air and ie eet ae 2 
days tor hardening in tne air. AS preliminary tests are the 


testing of cubes atter Sy day ia air and 6 days tn water. Tests 
of the neat cement are no. > Longer necessary socording 1 to German 3 fa 
standardaie AS | | aks ch ee kt } Fd Re ea 
Ip the German ‘suendards- is s prescribed vesting ‘by. parts by. ae es AL 
Weight. But at the pbuilding site the wixing is by: volumes, me ea 


ch bas the result, that cements with sualler ‘volune weignts reo, Si he ea, 
exnibit strengtas in testing, that can seldom be attained MEU ay een 


ig ‘dee ° r PR ae ry 
x 2 aii 
7 aS ra 4 
iy it nt 
bogie f aunt | a 
CAP ane Ser a 3N ? 
os pry Wiel al * & 
i bie! 2 
es in 


Fh is ae 


i 


wixing by volumes. | 

: 4. Steel Fortiand ares Lo Man Grenudated 

Steel Portland cement is obtained by grinding melted’ grained 
gee from smelting furnaces 1 with Portland cement clinkers, ‘ 
ey: from smelting furnace slag and limestone. Tae color of i eee 
stecl Portland cement generally varies. Trou light gray to erey- 
ish black. The specific gravity in airdried condition is 2.96 ne : 
to 3.18. ne fineness of ginding is the same as for Portiand | ae Nia Mae ae Rs, 
cewent, and also tae setting aod hardening periods, 4 ‘Yet it” : Pa ate lee 
must be recommended to make the mortar wits rather more: water . 
tnan for Portlana cement. The changes in volume are nowige aba t 
eater than for Portland cenents in experiments toe steel ‘Ports 
land cement evén behaves better than Portland cement in Peder). °> 
to expansion and cracks. Also a wovement of steel Fortaaad 2 Mai beta 
Cement is not to be freared. Once set, ait is as good as pede a | 
fected by frost, heat, bog, sea ana salt water. ‘Steel Portland | aes 
cement bears storage just as well as Fortlana cement. The eee ats 
rst judgment, that with steel Portland cement, on account of Pearcy 
its sowewfat swaller weigot ‘per volume, more cement must be Ps 
used than wita Portland cement, that tne work 1s. dearer, fas: Tages ie 
proved not always correct. Also in. regard to the strengta to. 
be optained, steel Portland ceméeat is not inferior to Fortland : 
cement. bxperiments of Royal bay gece Testing uacoratory at. 
Gross-Licatentelde. igiz. Heft. Se i 
Note 1. pe Si. SHerlting slag sand VS 0 etou silicate ‘poor An 


Liwe, that Vs granulated by running the svag ovtcined from sus 
eLsing Furnaces into coke water (sharp foundry aand”, or by 
changing VA Lato dust vy ateot or oir jets (the e\o8 appears 
US SRGLVL SnomelLed spheres), OnG Lau This way 1% ocgurires Ayara- 
ulic propertres, which. he SVOg ara HOV HPOSses previously. Dry 
Vag then FOLLous by a preliminary KEatrings An rotating OY URS, 
that are errteer heated ON SWSLUARE furnace gases or Oy a coa\ 
TAC My. 

Nove Le Po 32. Thar the slog sand hos hydraulic eel tae 
ond takes G@ Waterval part Wu the setting and Nordeninée vroces- _ 
Se3, was Lond veen contested, The svag Bana 1s commonly termed 
US G GiLuting woterrab of Portland cement, in the place of 
which wes ground sand could be used. Yet by recent researches 
tae Lncorrectuess of such assumptions has been proved. 

Note Be Po B2. See Lervrts. of UWnron of Arohnirtects and Bndine- 


Bugineers. 1912. pe. 127. | Be tee | | 
Kote Se Peo S32. Further see Msteck Portvana denans*pontess “ook. . 
and use of steel Portland cements. 4 th edition. 1944, Ry 
By tne decree of the Prussian Minister of Fubliic ica aah 
6, 1909, steel Portland cement is to be regarded as of equal 
value with Portland cement, and likewise. ‘Shall be ) dudged es bac 
Stancaras applied to Portland cement, aia | | 
The Minister bases tne issuing of his decree on a series of | 
@xperiwents, which gave been made in tae Materials: Testing habe > 
oratory in Gross-Zicnterfelde, and whose results by tne Gecis-— 
ion of the Minister were publisaea by the Sheath tee Commission 
3 Steel Portland Cement, nets Sas ib | (" 
The explanation of the “German Standards” tor uectons ag Le 
and testing of steel Fortland cement states (Dec. 1909): -— ae ee 
“Steel Portland cewent is a aydraulic cementing material, ¢ a eta 
that consists of at least 70 p.c.Fortland tement and at ‘Host | - | 
36 pec. of suelting furnace slag sand. 7 The Portland cement Ra 
is mwanutacturea according to the explanation of ‘the’ standards. 
of tae Union of German Portland Cement wakers. ‘The suelving te oe 
furnace slags are lime-clay~silicates, obtained from iron snel~ 
ting furnaces. Tney must contain forid i part of soluble silicic 
acid (Si 05) + clay (al 02 ay at least i part by weigh ot Aime 
and magnesia. The Box tioea: cement and the shelter. ‘slag must. be. 
finely ground, be correctly made in a wanuiactory, and he. eg 
wately mixed together. Sdditions ror special purposes, ‘partic- ‘a 
ulariy for régulating the setting perioa, are not forbidden, — TE 
but are restricted Bh amount to 3 p.c. of the total, te exclude Sey? ‘A 
tue possibility of additions: merely to increase the. weight.” Sh hae aes 
HOV] Le Po BSSe. Fut tHe omount. pee wae svae added is any. et " 


(ePmUned with GATT Vouliys there have alreoay been found QAGVGL—— a oe 
ons wp to Ai gece (instead of 30 pec.). Var 

By tae decree of March 26, 1913, tne use of steel poneieee 
cement is thencefortn allowed also for phe construction of re- 
inforced concrete structures of buildings in certain cases, @ 
and with special permit for each case, under the following con= 
QLtions: -- ; 3 

i. The rélnforcea conerete members are to be entirely protec— 
ted against tne entrance of Gampness from air or ground. 

2. In tae floors, beams ana Supports, are to be produced exp- 
ansion jolnuts at distances of at wost Z> m. 


37 

3e Sabvistactory air nardening of the cement is to be Shown 
by repeated tests. | 
tg eee to experiments at the Materials Testing Laboratory 
at Gros s-Licaterfelde, of Wayss & Freytag Co and other firss, 
protection trom rust of reinforcement in steel Portiand cement 
Exists 1a €quai degree as for Portland Cement. According BAe 
Contribs. of the German Commission (1943, Hefe 22), the benay- 
1or of rusty steel bars 1m steel Portland cement wortar is. aot, 
parently souéwnat more fortunate than in Portland cement. The — 
experimental mass was for 5 years exposed to the action of air, 
iresh water, sea and bog water. Cy 

Steel Portland cement nas already found frequent: ase. The = 
“Jnien of German Steel. Portland Cement. works” produces: for the 


trade annually over 235,000 tonnes of cement. This Union. bonds: ie 
its members to make the cement. exactly accorcing to tae descr~ nf 


iption. atin . Be 
5. Slag (Smelting Furnace) Boueutsi2 : 
Note 1. pe 34. The none of Mtmevi\ng Pornace ceoment™ Airet 

appeared in recent times. | iG 

Slag Cements are products, that are wade irom granulated. slag 
irom stelting furnaces -~- and as a rule at least -~ with the : 
addition or Fortlana. cement or hydrate ot lime. * Suen cements” 
can sometimes satisfy tné standards, but often entirely fail 
to dO soln practical use with otner additions. Fhey are Ob to 
be confused with steel Portland cements, woien in opposition | 
to tae slag cements, consist in the greatest part or Portiend 
Cement. But in Slag cement the slag content predominates. — ee 

Note? Ze He B4. AVL SlLOds have the peculiarity of setting ‘woke, a 
at alb or very Witte. Tne addition of | moterials COnTAVALHE © . 
Vime Vs necessony %O wake Their hordenind possivorte. (uiwe athe sy 
phate or Portlend cenent oVinker, walon Gbways contains | an bee 
Cess of VinelRSee Gemente. 1914. Pe 26). ; 

b. Materials adaed for of 

by frequently s@oveling over Soctiend cement with sand and) 
cravel or crushed stone (aggregate) with the addition of water 
ab the same time, an intimate mixture is progacea, that is + 
yaemee concrete. ? Tne size of grains of the aggregate must be 
détermined by tne use of sieves with cifferent sizes of mesh. + 
Tae density of tae material depends on the combination of tac 
grains. Sands ana gravels e6xa#lbit suca great alversities, trat 


36 
scarcely one sand or gravel is exactly like another. For the 
further judgment of the quality of tne certain sort of sand 
and gravel, besides the general nature of the grain (iorw and. 
Surface ol the grains, also the determination or the weignt 
per volume and the specific gravity are of importance. é The - 
chemical nature as a rule plays nO such great pars; tne corr- | 
esponding tests would ‘be ‘too tous thy and too costly tor | Brace 
tice. 


Note 2. Pe he The terns Seoncrete” and uortar™ ore. properly Pie ans 


BSYROnOwOUS, tHe sor+cablled Sooarse wortor™ VWs. tne mean. a wore) 
AOCUV BLE Gefinirtion would ve. the {o\Vowines -- concrete is om 
move or Less coorse-Srained mixture of brits of stone, whose aoe 
terstices ore FIVVe0 with REET RY {irst soft ond Mater Neel 

Jeninee On the controry, wor tar VS a. mixture of more er \ese : 


coarse sand grains, whose. Wnierstices: ‘are {Wea with o “unaigng 


WOLETLGY (aewent), ot first soft ond, Voter Rondenings or 
Tee Gerwan Regupations States em. Towped. eoncrerte LS. produces — 

oy Oo Wass Of SConorete Mm a wolst or soft state, Ynat only by 

g- wore or Less tauping attains: ‘the necessary, Seen, ick whe 


eye ea 


required strength. fa Ny ete CON ue 
Wote 1. Pe BB, For COUTse | grains. oS 0 yube. are used sieves 

with square neshes of Wee. Ma ae he and 60. mi wiath, ‘ona 

for the finer sand grains sieves with 4, Q, 20, 60, ee 


4. The WOLSPVOV to be examined is {ivet 


and BOO WEeSKHOS Per CR 
placed on the finest sieve ond shaken UREA nothing more falls 
through, whea the residue Vs placed. on the next coarses Sieve, — 
VEO. iy th 

NOV]? Ze Yo BD. Volume werent = werent of ao ward yobume incl-_ 
VGN Vaterstices. | Specific wevent = werent of unit volune : 
excluding crevices = specific gravity. Ve | 

AK a Yule are preferred taose habsrials, that in the given 
case can bse obtained at tae building site itseif (in excavating 
trenches etc.),or at least in the immediate vicinity. 3 Purth- 
6ér transportation requires time and money. 

Note 3S. P- 35. For the Larger buildinds one should not owrst 
tO Woke comparotive Geterwinations with aifferent sorts of sand, 
grovel or crushed stone. One con thereby not only avoid defect- 
We work, but also <= by a corresponding distribution of the 
Qearer and the cheaper parterials -- may secure considerable 
SOV VARS. 3 . 


$9. 

According to the gsbsrni Regulations are to be understood: ~~ 
as Sand; pit, fiver, sea, crushed sand, etc., up to grains 7 
mm in diameter; slag sand (granulated smelting slag of suita-. 
cle composition, pumice send and gravel, may also be used. 

As gravel; gravel, gravel stone, pebbles of 7 mm up to 7 cm 
in greatest diameter. 
lage gravel sand; the natural wikture of sand. and gsthierss as 
found in trenches. at bottom of waters. 

AS crushed stone; crushed stone between 7 and 25 mm, 

As broken stone; stone broken by band or machine between 25 
and 70 mm in greatest diameter. 

According to 4. burchartz, Gross-lichterfeélde West, for prep- 
aration of mortar and concrete ae following additions are con- 
Sidered. . 

i, Sand (heap of finest and coarsest grains up to 5 nm. (7 mm). 

a. Natural sand (pit, river, sea, dune, volcanic, ‘gravel i 
sand, as well as crushed sand). 

b, Artificial sand (for example slag sand). ©. 

Z. Crushed stone, gravel, gravel sand, chips (partly sand, 
partly more grains of pea size up to.about 25 mm). - , ; . es ae 

3. Spalis (aggregate, Chips, crushed stone, with graias over aaee | 
25 mm). Sh alle tA 

a. Natural stone (oapkea granite, basalt, ‘damestone, Bee | BRE yer es 

b. Artificial: stone (bricks, slag, crashed concrete, etce). % A ) 

4. Residues of barned coal(ashes, coke, slack, cinders). = 
Bor deciding On the goodness of the aggregate, the following | : 
characteristics,.come into consideration, according to Burchents. DN paki 

i. Nature of grains. a Eee GO ie 

a. Sizeief graing. - } | Si 3 Ge eee 
b. form of grains.” ae Wee ee 
c. Surface character’ of grains. “ eee of ebion S 
2. Density of tne pile. | ; Snes. sree ony © sea 
ae Weight of volume ‘(poured, famed, shaken down). Pa Oe A a Gt ae 


be Spefific Eravitye —  . ) ee eM cht ah meas SO 

C. Degree of density... .. Daan AS eee eons - 
d. Lack of density (volume of interstices}, 9 9 
3> Combination Sf dbatier AinusetTeh iat weeiesignus 18 shee 8 2 oc 
of grains in tne pile)o.. oh CERES Se . Rt ah eee Ie? Se Mime 


ae 


4. Qnewical navare. = heat ei 
a. Coe ‘in ts cof, lean (eosin or el . 
Ses oe ones ter) wi! 


vom 
Fi 


eS 


C4 
oar 


Ry 
* 


. ty aes Cae piel fas AS, Aiba Seige, A 
be Content in parts of other injeriows. substances (ana, hee ge 


peat, coal, sulphur, burnt line). ot es SP oS ee a AON 
G. Content in- excluded silicates: (volcanic send, pumice | sa- ‘vas igre 
nd, siag sand). “a wee te Ae ay ea gis wea hdc ores tee 
De ‘Strength ahd physiéal cnaracteriptioss SNE ce Cee ie ictal aaa es 
ay Resistaree to erusning. | ape ee 
. Absorption of nauer (poresity)< evar 
. Permanence in frost beacuse a Signs ee eee 
«< ‘Resistance to firee — Oe Fa aa ei 
Addition of Sand and Mater. — a pe a es Garls,. See 
‘Por. Bae intimate | cementing. together of Ge: araen acazesete, Berra 
is used: a mortar of Portlend. coment and joo ake ‘of mixed Kesey 
sizes from 5 to: 7m, vo0s. as large as peas. « ‘nis dees not need 
to be’ a pare: Quarts sand, “but may also. contain ‘hard: ‘Limestone © ae 
ash a a general bes eee: ‘between fee artitic: ee i 


send, pee as faite as peasia ‘ “bike 
free from adnering soared ois 


that no sulphur paren to. os , es ‘une. Bec: Pe ee 
a leas sk easily” be: ‘recognized by their: suiaing golden ye 
afne? > Sea sand. gan only be vgsed waen t ne. 2 lt is removed by 
Pp Vaspinge’ Slag ‘sand. obtained | ‘by, a1 @uulating, she slag) in | 
ing turndces, mostly’ pie e st 
at agence ener : 


CER COTES ¢ 
Tn » ee oy 
stpeugta of tne mo 
y ey i ¥ 
dake we ee SCPE Ah x 3 
he es a RRA. eae x * 
Phe ~~ ” é y 


ent sseegauh - Pa tame 
Kote ts Ps Bt. eon An poney sapectatly wrown eevee 
a) Voss)! ‘ean. proauce wovenent; : ‘e\eo areat Cane” a peaniet: ot 
water tsads PLasteringe rae Nee ee . * Ora aes ee 
Note Qe be STs the existence roe Lo Sakdy: alate eee pee eee here 
nVsed dy euvoing. ane Sand Cotwcen Vee bonds: WHEN ho gertaknie’ Ps ne an &, ee ah es 
warming occurs, ane worked VOoawy odor 13 pergeptivle. ~= 1 — nig oe 
the, Voon » AA SWOVN | ‘meseure) \s finevy dvetributed in the asks whe ae Sa a aaa 
Ve AS Not - injurious; only be wust not, Gineus: so [kbs Qvalase 5 oe ee 
NOte Be.Pe Be One can Judge of the somnyene of ONY Bort oft . 


Nee oa 


n 


Bey 
Bae cies 


‘gy 


tin 
ae 


P39 


Korte” es: De. Bee “pense “end As. ert seseae 


Cet Nie veins £% 
Stith hy 2 


She none angular. she \Sethens Anaswongner: she: veurtace, na ; 
 {ivwer Ahe orvgiwes ‘SVORG, Fron ALE. whe sand Os, ppnndeanh : 
also We stronger the GOtorete. Ca ee nee ie ee Fetus LN ana i 

What finally concerns the size. of, ‘aaaeies of the ‘sand. ia, e 
that ‘a Sand with mixed grains fap. to fe -pize) with a bigh — 
weight per litre asbest. foo fine ajsand * requires ‘the: ada 
tion of much water, and produces a mortar with ‘less strength, 


hile too coarse a sand would. demand to0 much cement. Brom sf 


‘ 


. 42 i FO Ree, RE A SARE oe 
Figs. 5. 4, it may be readily geen,’ “phat for cementing ‘vogetner eee 
the grains of sand, more. cewent is necessary in the first case a cee 
than in the second; for the voids are then greatest if the sand ide ae ta 
consists of grains: of equal size. But to save unnecessary cost A Tan ian ESTs he 


of freignt, in Host cases —~ without wore ‘thoroughly ‘testing : 

its quality -- will be ‘preferred. that sand located nearest. sie ie ae 

place of ats use. ees ee + ee eeu etae 4 ae $ soe i 
Kote A. Re 38. AccONaing to the ‘Bute Regulotions, | tine Wea Soe ea 

‘Aha® VV PASS. Seroudh | ey aleve with meshes 0.5 - BT AKS sine, she Peas 


Ouva not: OXCSSG, AO Roos Rhee. Austrian Regulations require, = ore 


ger BONG, V5 Pose being. ‘Vets ‘On oO hop re 900 meshes: hfe ont MER - 


‘with wore Oot wh Pager” ee ed, 


be. pare, ana ‘taas. ‘free ‘tron imporinies, me a “proper tempera 


dof ‘set bie 


eee eg 


and too ) cold waver "Lengsuens’ lie Sakae mater 


A 
¥ 


phe and sea. water 


i rye: 


poe sata 


4 Wht 108 J 
Pe 


Peat ea ee 
vices om 


anion autor: a oa aa 
the best caoice of the volume 0} 
ing and’ ‘the duration of the: : 


sat Pie yeah. So ak) 
-") Por 5 Sage Te “ eg od > ’ 
nyse ee ae 


ount of ‘ater added i likewis 


“gt ed 


a 
retes 
ae CRANS 
ht iy RT sk 
‘é phox 

al 
4 


nlashishiret ‘the cconorete only iebachth stay: aéae ae neavs. we 
tamping, indeed witn the observation ‘ofa shigat moisture. on 
the upper. surface, ehe sovcalled“swesting.” To ‘best the anced 
of moisture of. tne eonoret-morter, one takes’ a ‘itt ie concret 
in the hand, pressing it-into a ball with the fingers, ‘No wor- « 
‘tar mast “squeeze out. between’ the fingers, but it must ‘show jae 
‘er on. “phe. sonface, | the | ‘conoret: mass. ‘Petaining its” torn after 
opening bbe. hand, Too great an addition of. waterinjares the = 
strength of: the. conorete; ‘it would be. badly stamped, since - the 
Piiags’ would: ‘be too elastic. and Mould soften. Tenping nould Bo 
longer. ‘increasé the density, Boxever ab must (be ‘admitted, that 
a rather wet concrete ‘takes its -foru: better. and. ‘ascespecially — 
suitable for layers that have to Peceive ‘phe. sbéel reintorce- 
went. -- A rule. for. tae doce hol as. rather too cemagen 
too Little waters: Bos. pee wae eee Se 


ee 


concrete TW loove cast ‘concrete. The toner’ 
only tor taurie concrete. stractures ofvareet. \Woauivaek, ek 


not for reinforced concrete. It ‘eneats only after long nd nee 
vy tamping, since ‘it contains relativel 2D: 


pease ot 


antageous: th whe: use of this. Iara te fetes 2 ae t 


ytion of) earthedanp, ond. “soft Miles oe Mei ae 
Bar thesomp ce ose. ot concrete, “AOL oontetns ey so much 

woten, rar @usy | of ter whe. eomplered: Aouping. pre veurfece of whe 

GLE? vegins to. exude mater OF Pe Heats: under ppseheure et whe” 


Pa 


finger. Re ia: ‘ aa bak ee, peas we 

Soft concrete: NB @ woes oven on. igaetian, ae water 80 Weosuran, 
Shoat the .e8Ge8 of o. any depression. on She. cavreasy 1 hemped ae ; Pes 
of sonceete Temains - a Short ANwS | ond out: slomly: ‘O\soppears, 30 ‘i 
That a Condensing effect of: ne Souping Woy | StL be. CRPOCTOd, | 

The plastic (soft) concrete has a ‘sreater addition of . water, — 
basa ea bal addition of. water, “about re to® is. Pele of the =. sy Zee ss 
volume of the conerete. * Por reinforced. concrete structures oe ae ee 
itis alone Gonsidered, ‘at. least in the ~ension gone of ‘meubers - Pope, aa 
subject to flexure; > the reinforcement of wae floors are- ent=— Oy Seay ah vad 


irely enclosed ana are not visible on the underside of. the f1=" oe 


ee : 


4,44 hg Sage Pe 
floor after the centering is removed. Finally,a smaller addit- ) eee 
ion of water suffices for the supports, since there is reouired 
more @ sufficient resistance to compression rather than the ; 

ond resistance between concrete and steel. Experiments of Bacn + Ay 
have shown, that eartha-damp concrete aiter 25 days exhibits * 

greater strength than plastic concrete, but that in the course rae 
of time, the concrste last named rapidly increases ib ‘strengta, | ‘ 
and that after 100 days is scareely inferior to Harth-de@mp con~ 
crete. If one finally considers, that the placing and tamping 

-~ in consequence of less tamping --.preceeds more rapidly and 

Simply than with earth-damp conerete, then is one iddeed justi-~ 
tied in the decision, that the plastic concrete is entirely & Bik 
oreferablg to the other for tne purposes of reinforced concrete ro 
construction. With earth-damp conerete no such unobjectionable ? | 
enclosing of tne steel reinforcement oceyrs as with tae wet a ES fs 


Saxe ae ee 


concrete. 3 . " 
Note 1. 0.%42<. Bach, “*ContrLoutions on warine Goncrete Brocks: : 
with afferent AGALtVOnNS of Kater, as well os on the Gonpress- ! rs hai 


vVhe Strenerth and BVastiorvty of. the Sawee™ Gtutrgarrt. 12086 Also 
Bach, .“Oontrtourtions on compressile’ Blasticlty and Resistance 
of Concrete Brooks with varied Adaievons of Worter™. e 

Bach vas found shat vee Least quantity of WORE, THOT Just Stee A 
SuTt{voed .%6 produce Oo Nentoctsy: Lomped Goncrete, Secures the . 
WOXIWUR SLTASneTD Aas WELL as. tee BAYA DUM bond, resistance, oppor 


et es Se 


Vou of tne two sorts of concrete would occur. A groduol avatar 
VVon com be Mabe with wniforarly @Grth=Goup conerete, the Longy Sag Gooey: Sa 
Vayer after being placed An the form being sprvnkbed with oss nay 
woterimg pot ond then Tomped. The auount.of water odded must 6 ie 
ve SradugiVVvy veawood upwerd, The chiefs. edvawtage oft. ehis pros > 

cedure Ves 40, be Sought tn. the easier that, BAe Bochineg NOs, Oe be-” 
Viner o uniform concrete, aaa 
it oné enploys(for walls, Foundations ad ta : se), a Like 


sed to steel Vugertea in concrete ond pulled or pushed owt, Mi pee 
ASee Seotion VIL). | ag eA ad 

Noted 2. Po Ais "Por very ero mortar mixtures wth Wore Gems ve ee 
ent thon sand, Vs the odd bion of water to Ke considerably in- pais, 
ereased, wp to Gbout BO prt.” Kurtembers Regulations. ace: %, ee eae 

Note Se Pe 41. A Bhary separation in a Sirder -- under wet ol cs 
and Gey CAVE ++ WOW, Oe wren, ainoe then the Voter Separate che irene? 


or | 


oe AAS 
te 


est. cavities. The work pestis cenel al 


pis. ar 
bhp patie 


ct. 
VES 
; pk 
eS 
es 


7 sie. jae C con: re 
with a ‘snooth Gen nee eta 
does nob furtner iba ashy 5 


v 


gree. gor 4. ee 


than for a tion tear ee 
a5. Pele “of ‘the volume of tne cone wank 


Dax oitorapeasay sea 
‘is the fact that a very @ 

ascessary, which furtne ust have 8 
bo. rn ar 
Pica reacae amet » 


- 2 =. we ak act y jus 
si ln i fo ep 
an 


Fl 


stn a a ee ee 


in Auerd 


2O%e, and pected a 


Babe's 


deme Be 1018. ‘Vs Aho) s 
“Stone and is 


“e 
gt 


| PERG a 


erials” found’ ‘in ‘the pad: eee Ed 
they are” ‘suitable ‘for use. In any case, the stone poco ! 
waking the concrete mast at least. exaitit @ resistance to ella 
‘Shing 2 jal to thay of tne hardened mortar. * Bor th. 3 reese a 
‘right bard stone, sharp.edged, such ap granite, gneiss, Lt 
dolomite, . grauwacke, ‘bard. Timestones, “etc., pry aneietasha 

recommended for making - concrete, and the use of sun ‘stones @ : 
always results in ‘considerable’ inerease in tne ‘strength of the 


concrete; tei but. a ‘areater ‘eagition of ‘Stones tha: Sa Wo 50 Fate 


of the. build 


mi 


r 
* ~<a, cae sy * es pat 4 7 ers 
‘ae so 5 ; i. / % be “ A yA ‘ oye Jw 
. . : is * LO s + . 
Be syle i ‘ . 3 WS a Ay. hg esl whee) iS Nel oz Sa ‘ hee 
= 
' pe » Srv > 4. Se 
; at vote 
Sa rae Ye A A ae 
4 x & ED age Q 
Me ‘ “3 i“ 
is ‘ f 


Paes 4 oh ys 47 2%. 
46 pen ie PV hear Gee tenes 
’ ede x Be cay aa \ Pane Liat £ 
2 ® - Mig : ‘ AA - 4 ‘ 
: ee haga § 
a 


in the hardess: of the crushed stone ip ivselt has” no nee 
nae influence en bane. ig ghoraheee of the concrete. ‘Bor example, : * 


rete of erusnea hinestone, atinouen basalt as about a 1 simes 


La gai, he 


ich 


do nob exist. in ‘the: vieinity of the. ‘structure, Aig wai 


7 ite, de: AL 7 


‘tien of erusned stone is. certainly connected wien a Gonsia aa 


BS 3 


ot. 


Rg 


more: thon 10 eee ot aesctiee 
° ih 


Ra ay a 


tatiasahs eee aaee: 


i > &. 
Bea ie 


Ue Min the sonoice of as. 


ax «r, 


pa phe 
fore Oey 
& : 
ey a 
ee Paes a) eer eds 4 
a w 
} ad 


mal he 


? 
a 


Srow ee As 258. works ‘snoorang xo “nartbaen of. Ald stone. Mga aw 
ue ‘Wery good and also cheap. kind of ‘Stone is gravel, since in eR. ar aor 
Consequence of the most varied sizes.of grains, it requires: the SEER PERC naea sb 
smallest Quantity of wortar. fine éragns increase the tensile © ee eee 
-strengta, | ‘Coarse grains. the resistance to. ‘compression. ‘Yet. une 
strength of a gravel concrete does’ not ‘@ttein ‘an equally: high 

degree @S a concrete of crushed. ‘stone, particularly when the . 
_ Gitferent grains are ‘Rot angular bat; round, With angular. ieee 
‘the crevices. betneen the graias are naturally ‘Less. then for beat 
Fang grains. fhe tamping drives. the: angular. érains: like saa gee ey ae 
“inte? ‘the: erevices ‘ot the adjacent grains, In general, ‘pia s | 
‘Stavel- as. to. be preferred to “river. gravel, since the latter @ 
- contgins too little sand,and also the ‘round grains are. too. ‘sty 
00the Sea gravel is. indeed very pure, | ‘but. frequently contains 
salt,. ‘which later ‘orystallizes: out in the completed. Gonece ie: 
Gravel must be. chiefly composed of quartz. or ‘sbrong Silicious 
STORER, only. exhibiting a stall portion of ‘Bandy aixtores. =. 
| Mokena. Radke Gary has - waeed established, | ‘thot, round grains wee 
wader gone clrounstances: Con: Give Wigher. resistances. biked 


Ang. Way gnguvar grains. Round Aes \a: ere: Pape oem eau 
eustiy mixed ond. Fomped, | | te hs n ee 
Ganally, @ravél may also occur in nature ‘bized with sand eo 
ne alled“gravel sand”. As a rule this. presents the great ore os 

eof being ‘cheap and easily obtained. Its: use| is: andeed ttc eae | 
forselaen by. many-otficials, yet it may be used ‘without risk, Ea ce 


With approximat ly the. Tigat ‘proportions of sand and. gravel ae : 
directly for. ob ‘baking of coharete. Necessarily, the. ‘Content ere iagttac tg 
-of saad uust be! accurately. determined by sifting, and. ‘be OOO) le 8 ae 
ected by adding or removing sand, Adwirable also is an a ee, os 
on- of spails, for: example of basalt. Chips. Tf da ‘this manner Pig as Se 
the use of a gravel sand be guaranteed, then ‘is eb to be ‘pera-— Sieh tok 
isted. tor the. construction of reinforced Concrete structares. # 
Only ‘for stavically signly. stressed structural wenbers (frame 
beams, pivot ashlars, ete.) are necessary. certain. considereti- 
ons rélating to its use. . ea. Se Te age ek eg 

Yote 41. Rie” AB Hoe | “inf uence. et. he Size OF Grains OF Gravel ee ee 
Sang on Reststence of Goncnete to Crushings® B & Bs 1244 Re 3 
488, 193, 264. Also Arm, bs 1042. p. A154, y 

Pumice gravel sand (see p. 38) ‘affords many - advantages, is 
extraordinerily light, ‘ansaleting for popes and. heat, _ bat is 


‘ 


a ae | 
dear, Mice in consequence of its porosity and small tensile 
fesistance is very much inclined to shrinkage cracks. The per- 


missible stress on a pumice concrete (witn at least FOO EE Be OP GP ag . 


cement /m> can only be placed at about 15 to 20 kil/cué; for = 
higher values is necessary preliminary evidence ‘ot its resisBy 


ance to. breaking. Fumice gravel requires abundant addition of eye oe ae 
water. in taking the concrete; likewise the concrete ust. be. > : 


kept ‘quite wet until sufficientiy hardened, and be protected 


fron ‘Sunshine. With too little water content, the pumice -conc- 


On for e car of 40 tonnes about 12. a “puntee, gana. or AS: we of ‘ 
PURGE” gravel. pote eae ee ak tot cr ns eee me ae 


action and covering, ‘where no alternating stresses: and dynamic 
intlueaces are to be. feared. ‘(Ror example i cement. +2 3 pumice Mie 
sand+ a quartz sand), ‘The underside - can be. plastered with cen- 


RA 


steel” rods. and expansion joints: are: ‘provided, Ivis not advis- 


rete absorbs” ‘too mucn water trom Bhe cement and. permits snrink- Dea ape aa? 

age effects. It must not be $00 > strongly vanpes, so. “that pumice pe eee 

grains are not crusned. ee erie gine 2 el ee ee eae PS eens 
“Xote. + oe AS Bumice SOnd | (graine o 40 40 WH ‘atoneter) costs. : ss ae em 

at the Locality. (kewwied-o-Bn, ) aban marks\n®, One. Can weaky (8 64x. 


rec 


Pumice gravel ‘is: ‘principally aeigntie for Ligne roof. ‘constr- x 


nt. paste and twice coated with line. colors. ‘The slabs (not x 
'-beams) are, made. at Teast 8 om ‘thick and sufficient. dividing 


able to use ‘pumice concrete only for the ‘tension ‘zone with gr- 
avel concrete. tor the ¢ compression gone (to lessen ‘the weight — 


of toe Prabhat since a deter y SADSEATECR, of tae tno kinds of 


aie ae te nd on pincnoetaies 
| at see tor of seat, and none ae 7 © 
The Bbc vat cep gg ag | 


1 Ere o3 
ph nas i Ke ‘tan Se Ate By 


but smalls es: o- 


hy east 6 weeks in the open. air. ‘before : using, end during that 


a ek 


48 
suall; the slag may destroy the concrete under some ‘circumstap— 
ces, and in compound stractures,especially WAtn too lean a mix-' 
ture, the reinforgement rusts in consequence of the contained 

sulpnur. * The slag must have an acid and not basic reaction, . 
thus not redden biue liwmus paper, It also easily ainckines. to. 
shrinkage cracks and movements, especially with. boiler and hee 
arth cinders, and frequently nas a shining smooth ekg surta- 
ce, to which the cement adheres badly. : 
Note 1. pe AG. Especially garbage cinders. See ‘Rowse, fevers 
pe 46%. Goal ciuders are always more dangerous shan snelter ~~ 
SVOG. ae oli t 
Hote 2. Pe 46, Burt the esVicotes of ene\ting {urnaces” slags” ie 
are Wieghter than iron ond swim on Vt. 08. a protecting cowering, Feu vs a. 
they are Let ours by a special) ‘Opening. : Ie eek | 
Especially dangerous is the. use of fresh, “uaseasoned eis 
aid cinders (coking, hearth and boiler ¢@inders), that merely ae 
contain unburned parts of the fuel and free. Sulphur. They pees 
ord opportunity for the formation of cracks and ema rapidly : . 
destroy the entire structure. Slag from’ fires must lie for 8% 


bime must be Shere wALy, fabiieety 80 ) that the “pose soluble _ 


basal t-like Phowas pig. iron ere since there’ is top be pate & 
a very eagidumutos /< ey ce and, sisematinsin ‘The use. of tee 


ald ptaceed, te very great caution 0 ae mae eof nag oe 


Py 


preserved Nis cubes a grave’ Gur ing. their hardening, waive OA Ee Ay 
the WUAVEIRE Of ficialrs | ade theirs. ‘An SVG. Bands ‘This Nod evar. ae ee 
eurthy gosorsed the water Atom, the oubes, Bo. wnat she water ves F 
quired for Bovrdeniag wos Vacking : aoe whe. OMNES » ‘<= In ° Westra Raion © 
Von locality, under the worker: place wos. a concrete sewer, parte ee 
Wy covered by sand, but party ‘oy Veen slag. When: ‘otter some ees 
years. the Pavement WOE TENSWSs AY Gs | foun phat Ane concrete 
mas 80° ‘stroneyy | eonnoded, Sei whe shes, vnet 6 greater nestorat. 
von ‘woe necessanys Under the Sand The sane ener was verteonty 
preserued without Angury. FRESE ae a0 uy ae | Bs 
Burt on the other Bd once ottietat “expervacan % aa as 


aiwiler to Reine gravel, bowed, <a eee 
gravel concrete, AG * ae Laden ee jane _ . 


slag ore produced ens ys for wpten @ “Settee be. eC 
-wouba. | arte 
rewoved. to abtain room,  . i rata et Ng. | 
Purther see Z & B. 4210) ee uty 190, A@tAS Bs a 
the sources noncd ON Po BSB Mote Be ee. 
A Goumission of Officials. of! ‘the winuader 38 ba : 
of tae Ministry for CollWerce ‘amd Industry; and of the Mibieing 8 NE 
of Worship and Bducation,. ‘eainell as delegates from the Union es sy 
of German Swelters, from the German Gonerete ‘Qaion, from the. AD Hh Nae 
Steel Works Society, and from the Bngineers” Society, wade a ee kee Se 
tour at the end of 1913 for visiting a large number ‘of SES Laoas ee 
The Commission had in view an agreement on common measures MAG ae Gk 
also-en experiuental programme, to produce a clear understande = = 
ing of the usability of smelter slag in construction, 1» The emp 
eriments are now proceedings 6 oes ; | eR nwa de ash 
4s for the size of the grains, for gravel aud erushed shee oe 
this should nob be. ever 5 to 6 cm in diameter, tans not exceeds — ey an Rae, 


ing tae size ‘of ‘pea’s esses, but Also other: sizes. may exist BP ots Ri. 
to this extreme ‘walue. This is especially true ‘for ‘vamped | Ome OS OE is 
crete structures. Stones under 5 to 7 mm diameter are to be a SIRES i 9 
garded as sand. fhe proportion of sand to crushed stone or gram Se at oe ee 
vel is to be determined by sifting tests. The sizes of étains ee 
“for reinforced concrete are especially arranged*according to Ao 
the thicknegs and massiveness of the struchure considered, and 

according tq tne size of tae meshes of the: ‘reinforcement. For 


50 Geek | Hig os 
solid and massive parts, where the steel rods lie at wide dis- ns 
tances apart, larder ppeces are allowed than for other thinner ie 
parts with closer meshes. In all cases one will always do bet- 
ter -~ in the compression zone -- to make the size of the gre~ 
ins as large as possible (but for reinforced concrete at most 
3 to 4 em, since thereby a higher degree of strength may be @. 
obtained, it being naturally assumed, that tne resistance of 
the grains is sufficient. In the tension zoné is employed at 
most 15 to 25 mm, or in any case even 36 coe “OPSLNGe 8 Os, 

To wake possible ar -tntimate combination of the aggregates 
witn the other materials, it is sometimes necessary to tree at Be 
from adnering eartny particles shortly before ube, ‘Such wasni-- oe 
ngs also nave the advantage, that the still wet stone ‘in the rae 
proper waking of the concrete absorbs less water from the cell~ ee 
ent worter, than if it were used entiely dry. On tne other hand, 
‘experiments have taught, that many - gravel sands. ‘in Wauhed joghe 
dition exnibit a smaller resistance than in an unwashed condi~ ee 
tion. (Also see p. 38). Otherwise sucn washings are tolerably 
dear and troublesome, aud can properly, come into consideration — 
only tor the larger factories and tae: great. building localities. : 

Fig. 5, shows the arrangement of a washer ‘for crushed stone, 
as employed in the construction of a bridge of the local road — 
Agomitz-Klaus of the K. K. State ‘Railway. 4 B is the jaa 

Ailend F the completely washed crushed stone. ‘Bhe ‘otherwise usaal 
arrangement of pipes is replaced by 4. laborers, woo ‘shovel the 
material from & to D, D to ¢, C te 8, and finally to ae ‘Phe | Wee 
water flows in the opposite direction from A to 8, so that the 
clean water neets the Pcasrcad leaned crushed stone int ‘the ta- 
nk Be - : Ph Se Seta SR I oad 

Kote 1s pe KG. See B Ye he A910, pe AB. <+ En veg 

bghhig'e ghasre 2 without saaivtetias mee ‘3 & Be ast ms 


ige age > 
ae 
* y <. = : 


n> 


ate 


, a” 
gee 


Me age mild s ae 
PID. to tension and conpreseioe ¢ about 4500 
; ) 


mae 


tiga resistance of. he! ‘concrete cere 
SHEE. does not eireens & parents: eo 


GOWSE VHIO constaeretion’f cae ee 
Before theirproper use, the reinforcing ro 
aned with wire prasnes from all paint, 43 
as trom rust, taat loosely adheres. If the nus 
erent to the steel, it has ‘no: iajer } 
‘produce a stronger boad resistance, woile dust ana” 1 grease aime 
inish the latter. Many regulations require a previous coating | 

oi whe steel with liguid cement ‘(pure cement wash or mixed with” 
sand 4:1), whica is indeed very goed, but. not alnays ‘Recessary. 2 
NOLS 2, pe SO. Sleaning: WL ‘okie, otb, wawe, erse, Ve ko ey: 


bisatis ‘9 


Ve QVOVGed. Ero eae leer SRS ee ile. ak didenit a PSs me 
Professor Germer in Stettin has- eutavid anoay: nat the. ‘bond Baas 
resistance is very uniavorably affected by frost, bot phe bad neat ; 
eifect 18 again completely removed by Coating the steel rods Ce tt Se 
with neat cement. Other experiments have Rlso shown, that ste- sae pea be 
bart 


oe n ao > exe i 2 3 
J fa 7 eet ; ‘i x ; 
< hex 


52 | : ey 
steel previously coated wita liquid cement has a. greater bot poe er aes 
in this concrete, than steel without sucao a coating. A previous Pear ie 
coating is also recommended for the case, = ‘for. example for em a oe 
foundation slabs -- if steel pods. must “be placed in ‘leaner Rh 4 : ie 
tures of concrete, but without having to fear later effects of 
rust. -- For ordinary cases ‘however, one 9 may OWL a / Prevaous: 
coating ‘of the rods. | migre a eee 

Tne steel is best taken to une. “place: of use in equal. lengths fae oe ; 
ig possiole,(8 to 12 m), and whta the fewest possible reales Ee 
ces in sizes. Greater lengtas make bigher cost of ereignt, ac . 
gnd too many slightly differeng sizes 3QF-. rods_ for the same we 
liding give opportunity for wistakes. For example, for beams fas 
and supports are taken 16, 20 and 30 a rods, ‘tor sleds to and 
13 mm rods with 5 mm for bbbkberct Ee 


ces to ue8. bie ands wath ‘nooks 20 Hed 

with. wire. (Fig. Ode. UES Oe 
A distinction is ¢ snerally ro) ‘be made. ev 

pression and in ia 


rlfs 


Anan eeua ‘or pressing vogether oth the bakpoes: xO ve melecd ‘se 
RECESBATY For producing: the ‘Junction. Aajurious AS the Foor, - 
thot in ourtogente welaring a UTR ENG of she, eteey hoe whe evens 
Ley of the weld con BSOTSL bY | ae BVoVaed. peers 
xperiments of German { Commission’ for Gbintenied: donoretess g 
theft 14; Experiments. on Eeintorced concrete beams ‘for determ-— 
ining the resistance of 4 SB: the steel. reinforcing pea 
have likewise shown, that wita bota: ena. hooks. as well a3 the 
winding with wire are to be- recommended. fh Pe : pees 
The cutting of the rods to definite lengths is done with the Binds 
flat chisel, indeed eitaer cold ih or bot for. strong steel. S* | 
But men generally employ special machines, tne sorcalled steel ae 
shears, easily portable and driven by and. + ‘According: to 8 size ive 
of steel will tne red be turned over or not. Th€serodg are also- 
cut witn wre or plate shears, or by a bolt cutters Larger ‘rods be 
(for reinforcing beams) are prought. to ‘tae building ‘in tae Cor- as 
rect lengths, if possible, in ‘order. to avoid. the work ot Cutt ae 
ing and waste, in spite of 4 higher. price. Wastes’ ‘from. thinner = 
rods (reinforcement of:siabs) can be more. easily utilized, BE ss 
for large rods (over 2§ um diameter) abrupt bends are necessa~ PERN e Oe 
ry, then must tae bars be-first heated at. ‘the. bends, ten bent Be aS 
by nand (Pig. 7). Sligat pends can be made cold on & mould by 
hand of with & screw press. In a timber are set iron, a cs oe ERS A 
against which the steel is placed and bent. As a test ‘the! beta ee 
can be sketched om tne drawing board in chalk and tae red be “es | 
isid thereon. Points for bending are marked with chalk, never ites 


with @ chisel. Fig. 7 shows:a bending plate, into waich are set: - ; roe Oe 
Strong pins or bolts to serve as tae, form. 1, ‘the bending of tac aS 
floor and beam rods is done in the Laksuids neforenand,. oat pos- Sick Sa 


sible, and the steel im. prepared condition 1s° delivered, ye : x | 
rail or wagon. ae & ; era ese ae Be POM E < aM 
ae La De 32, prefteresve are Such erent cuskenh: ichere tne. 2 we 
rodj is not passed in fpom the side frequently for severe’ yards, > 
but where At Gon be wah ladda ini pes a hate et tahrud at the deat- 
red povat. t . eget ; 
Note 1. pe B36 Ou ext ihbake and sends, also See Section Kil. 
Lt shouls be noted, tAGt a SUCLLRA percentage of sibicon or ip 
Phosphorus Bay be unpleasant for vending, although Vt does nor . ‘ 
Unf avoraoly affect the strength. | | 
The beading of the rods requires much payment for labor. Th- 


54 

Therefore tools nave been wade, that make 1% sédeibiw to bend 
cold rods up to 4 cm diameter without much labor. These tools. She ae oe 
allow the prepabation of the rods on the building >ese itself, sr ee Pyle 
so that no mistakes or losses can occur. for example, Fig. 6 pee pe ae 
shows a rod bender eae ef vaalts by Pfeiffer and Ludwigs, vo ee 
Mannheim, with which rods” 36 wm diameter can be bent ae 

The former ‘generally careful ang usual preparation of the | 
steel in the swith’s shop is not only lost time, but also. req~ PE ee AL 
vires considerable cost of transportation, nat will be avoided © va 
by the use of bending appliances. Tne rods are. taken. ain vaeir Ae 
usual trade lengths to phe building site, and as. ‘peeded are a 
quickly cut and bent. fhe foreman ‘can take dimensions ‘at the bs a Moa 
place and then Dave tae steel prepared at conte under ‘Ris. Bates a 
sight and placed. The small seraps amount to about 10° PeCe, S Ys 
and canbe used for single and double storcups, or. for. larger — ae 
diameters (more than 5 to 7 7 wm) can be used for anchors, dines oe 
riputing and supporting rods, or also for reinforcement of va= ae 
ults, Tooblues, etic. Posaibie. alterations: can be made ae once» 
at the Site. - . Sar Me dee 

As for the. section of: the steel, “the round ‘rod. is. he. most 
common. + Round rods favor the escape of air and ‘the Saeed De ee 
of tne concrete; also they nave no sharp corners , that cut es : 
into the concrete. Any later alteration in the st: structure can oe ae : 
be readily considered, which is not the case With rolled shap- ies A es 
es. Tuey are also to be obtained at ail times and at any steel BPE Tete 
store. It is indeed injurious, that the. round section -- tor. be Be 
& given sectional area shows the suallest. cosificient for bond Pp ater 
stress» (see Section VII). Flats and squares ere also. employed; 
that are sometimes twisted ‘about their axes: to increase baeir ee 
bond resistance (Fig. 9), indeed after previously heating. (to 
(Twisting cold produces anfavorable stresses in. the steel). WEN OKS 

Other sections are tne +, T pk and S$) shapes. Further: sn ea 
ular and square rods #ith concave sides ‘Sometimes: cone Bete AO By 
use. * 3a ane "ak Bea soe ae Med Bate cae ee Pook co Voces 

Norte Le Re She But Ve Ve. sdoisaple £O. est. whe sections On ee Ni either ce a7 > 
Gevivery, Since. chere was. oceurred & aAfterence, Be “Xo paar ke Gee , 
between the ordered ONG delivered Bteee eet oi ae dees wk 

Note 2. pe She AVY these especial. are: (Ransome, qhoverer, Re wera CG 
Jownsen bars) ave dearer. thon round OS, they: are more | ipeiwen oo ne ae 


(na Awevicae BXySF \RORNG: rove besa teased’ the varying sections Re Nea 


WV 
2 


San lithe 


This is races about the rods, hela with: a eee 
fastened, Por the Stirraps. (see. ‘Section. ‘RITI) are use 
rods oe to & aa ‘in | diameter and sometines, ‘thin ‘flats. 


Aiso- cecanehy. various ‘geoiel Bank: are in 
certain advantages over: round rods, They maureen ee a 
Pile seearintectoney seeegaaenta oe tne ues espe nd a 


kewise eateany dependence » will be ple 
workmen eutrasted with: the p execution, 
nohtna shapes, s 


eh goo" 


aaa ake possi 


vii Ce a) 


point was,. that the ‘I-beam q mien onployed'ian: Ree: 


PeRCe a a, 


ion alnost ales cansed a Sacer? of wal perial. 


sonpeenekae stresses: before ‘tne rake. ‘of ‘Ses 
tar the setting the apper flange he, removed, ¢ 
purpose is transferred to. ‘the concrete, pares tes ribs 
igid, p. 104. epee Mad eee 

The rivetless: lattice divaer Gig: 4a) ét a 
of the Rivetless hattice: Girder Ca,” Dissalgort,, “be. 5 pressed ae 
from a flat” plate with double’ CUTS. Lt: consists ‘of. two bottos. 


chords at the same beignt and an upper chord, “TaliA) Sptoabal 


by inclined bars | on ‘opposite. sides and directions. Suen a lat- 
bice .beam aftoras a. taal these connection of ‘tae compression and 


beam, gti ps 


tension gones of tne ooweréte: a25 weotnakig: anchored in ‘the eo Aer ee 
concrete, and ‘joins without rivets all tension and ‘compression nee 
neinforcemens, stirrups and bent Bods. he firmly enclosed — ns ay ec so 
‘oblique’ ‘struts reteiveg perfectly ell shears and bond nsreasen,. 
and furtner the- ‘side bars. ensure an increase of the bond oa 
tance and that to slip. The lattéte ‘pile is delivered geneletey, 
it requires pO preparation at the building. In consequence iat > Beye. uae 
its stiffness the beam can. itself support & part o of the satel os 
ing, therefore reducing the. ‘number of supports. The. pean Se Wat es, 
placed on the market in various. seotionse FO 
bo De SOs Bee SawdwWNen HVS..H. BE. 
Kann bars are. angular bats, eens two opposite angles have Sgt! Ey rer ort 
wings. (Pig. 12). Tonard the end of the bar, these wings are eee. 
cut loose, bent upward and utilized as stirrups: TO receive: the 
shears. (Fige 13). Thes they are firmly connected with the main pe 
bap; any slip of the par in tne. concrete is ‘prevented, The og 
nn bars come to tne building ready to set, indeed in different 
sections. By the Berlin building office nas been alloned for ee Gee Sead 
Kann bars a tensile stress of 1200. ‘kil/en? ‘since igi2; eatowie 
ated proof of the agai tude of the ‘bond stress. as not required = Bes ttee elite 
nere. * fxs ba sal Tae Re we | et Oe ea ae 
Kote 2e Pe. 8. Keown pare. are | voted with aecttonat OReos ee. es 
of 2488, 5-40, 8.95 and 42, 15 one See ersten ‘(Port Te . he ees 


i 


COVENOKS Be Ue Cte ae ae aie? gpa er aay 
piksaae the use of expanded metal | as “reinforcement for 1 reins 

forced concrete structures remains to be mentioned, Pais isa 

wade from a steel plate, which. is slit ‘by a machine and ‘then 


re 


MELD T 2 Psi 82 ie San 


stretched in a direction perpendicular to the slits to aa 
lattece with lozenge-shaped. meshes. pe ade tec ge 38 mie | 
ROG Be Pedby Axpanded wetod (ave. AA), cones” Aw consvaerarton 
especially {or ‘simple structural members. ‘Qualia, foundation = 
SLave, freely eupporsed Foor slabs, ero.l. “Bhe feor Anot under 
tensive atrese no auff{icrent vestetance as) deflection exists, | Rect Ce au 
has beew’ dveproved. ey experiments, or. pret oO Vengthoning of 4 epee 
whe nerteork was possieles the, goncrerte. ramped between the mesh a1) 
es Hinders any ‘ohange , of forme the Voy tng of suew a newwork mB ot coe 
procesds “rapidly, yet. ne right siructurel Vengtns. a0 not: she- é % a NES 
Bys @xVEt. Likewise the velaf ofcement cannot Be. 80 sdapted to i ei 2 
the course of the Wine. oft BOBCATS, | as As eusihy possible for | 
YOUNG. TOdS. -= See Kersten, Port i, 7 +h editions ive be aH 


r ; : 
2 a oJ . é $ ry n . 


57 

‘the system of “Schroiff Steel @oncrete”(Bielefeld) ases thin- 
ner but strong steel wires. The advantages of this system are 
of ten only of a quite conditional nature, i nae 

Note Le HeST. ALSO Bee the American canstructions WLdh wire 
BELTING ve\aforcement.s. B & Be 12909. De 138, 1914, Pe B41. 

‘Hor supports the use of cast iron may finally come in quést- 
ion. €Spirally banded cast iron”. See Section VI. 7. 


#s 


? 
‘ 


: 58 
‘SEOTTON Alt. WAKING AND US& OF CONCRETE. ae hag saNag a are Goge® 
A. Hand and Machine Mixing, = Ghee fs Ea 
After delivery of the Portland cement in the pwiemeay siekis: 
ges begins the proper Mixing of the concrete, indeed as a rule Aa pha ne hc iy 
by units of weight. The Prussian Rgaare tions, prescribe: the fol~ eke pees 


" lowing: == Sea, ee 
“Tae concrete ‘shall be mized by ‘units of weight; as. a unit er eawce oS 
shall be taken the sack = 57 kil, 2 or the barrel. = 170 kil ane a0 Tene 


cement. Phe additions may either ‘be. weighed or measured ain haat ‘ 
sels, whose volume is determined. previously, to that their we- = 


ight corresponds to the required mixing propertions, = et: ‘ 
Kove By ps B%- Te South ond mest Germany iaceus of SO.HHL (> ” A 2 een 

36 Vitwes) are’ isd MBE s A ack of ST ¥AN SOTERA EARS to ANS, eosk | fe ees 

(= 4A Nitwes). Paes | Va 2 


The wixing. ee, ee eonorete must toviues: ‘int such, ttanner, mee es 
the mass of tne different components always: coPresponds: antes 
iy to the reguired : mixing ‘proportions, and Can easily be meas= : aoe 
ured. In the use of measuring vessels is’ whe filling: to be age A 
so as to produce. the best poseibid onitora aes of the Sg Toe ee: 
teats always in. the same way.” ee 
Phe reduirement of mixing by. nits of weit is therefore 


RAN 


nee on wa 


RS e 
‘preseribed, since: ‘the beaks’ of ‘the contents: me 


otherwise. At this time coment Vidi shaken ana vessel ati 
definite volume does: ‘Bot show ‘the saue meignt: as loosely. poured — 
cenént. Damp. gravel and sand. neigh more than aa dry. Yet ee aD 
practice wen for econonical reasons: almost ¢@ exclusively uae wo- 


oden ee beemtnisinsas tenia iio se baat th 


plasform) ‘filled eet 
Bie dawas tae eas are 


: se eetiais ae hie 


reral | | 3 
Na cae ana %; 
its viii Soe ed 


land’ cement is ves as gi. 


and sand are. to be ci 


Nr t 


“wnoertota neoubte, tues : ane 4S. = San eee 
Ae Ore din Switzervand | One Wn Brance: kavse ¢ eer 
sana Mieiisind provorstons ore thean tm 


i > *< hfe 
x, in % 


e 
he epererant asters - 


Se a Ae af 

ae oe wotar Beosures ane t 
stnee by st eX 

ote aepeb8s But + see es 28, . kote 4 


xing “iteelt may’ then ‘follow in . 


eve cose cleat, 


¥ 


1: 


and to. cine Toei 


ear 7 TAL 


dette cunt of 


COIR LESS 


in ansiore: ‘nickiesss | 
b, ¢. Dry mixing: ee 

ent, beginbing at their fe over 1 sid 

pha tiorny hide ‘Shaking ge a tr fe: 


ci Pe eee © 
ee 
z 


i ee 
retwihe 


ee age an ee : 


siaptat ved: seu nar tan ee 


fe Wet mixing: Wc ns another wasted: 3. te 4 times. Ea 


: Snoweling back ‘and’ fortu uNae for ary mixing), ‘sprinkling’ ata 
"the same time 4 by ‘the man G, with strong | phing and mixin} ‘ 


pe 1 ys 
: bat ’ Wa : x Tee 
MIE Be . ‘ : 


= RAN 


ie ee Te ee 


ae ° ; 
| ete 
¢ Lé 


ee Pe Mtg ys ene iin diy 

at the same tine. The whole beri neither show streaks Becher, 
Spots. ag: Tah, NFO Meas gi aa 
Note 1. Pysee the eyevxiny leo:  trequentyy ocoure yoastane | pee as 
shoveling Ovgr, or before the addition of the erushed stones a 
~~ The Kowourg wuLvaing officials, for SROWPLE, presorvoe,. tnat™ 
ine water ‘Ve {rrst to ve oddes to. the ary “WAXtUTS, | only when 
\Vts GNC ferent. Components ave veon wixed together.” The ree 
berg Begubations (19412) requing. whe some; they Gewand waxing : 


tnree Limes any ond Tour. tines Bete But mony workmen firet ion 
make the mortar (oith the addition of water), whew adding - Ane eae 
crushed stane. (See Kote 4 On Pe 63). % en eres 

g. The wass is brought inte a neap and ‘is reedy for. dee, 

In tae case described, 3 men are employed in‘hand wixing. © He 
Two wen woula suffice, when the ‘sprinkling already occurs” bet- 
ore the shoveling over the crashed stone, Tae work of whe ‘ira 
wan C -- raking and sprinkling -- would ‘then be done ‘by A or Be 


if 4 men are at command, then larger mixtures are. made | On ae 


then best placed as in ‘Pig. 46. The nixing is Givided ia “the Hs 4 
work; A and B shovel one habf to one side, ‘C and D, ‘the: other 
half to the otaer side. One or two. men + in rapid work scan 
finally take the raking and sprinkling, as well as ; pringing ae 
the materials. | i ape ee 

Note Be Pe Be A aeeee ‘et AQ Vaborers | con vn ane yay wis ee 


this manner 15 to 20 we of CONCTSTS. rhe ‘ oF 
Naturally all washing while sprinkling is. to ‘be. avoided, and 
an entirely uniform distribution of the water is intended by Soa 
Constant thorougs sooveling. Fhe- entire process: ot mixing weay 
be completed rapidly and without pauses, ‘since: after watering eee 
the setting of the cement begins at once. ‘Therefore the quant- 
ities wixed are to be {so measured, that they may ‘also. be mgd ae 
red in a brief time. jin warn and dry weather the conerete bass 
‘Hust not remain more phan an hour, or in ¢ool or wet weather 
more than two hours béfore using. Concrete not used at once SW ate ee ee 
is to be protected from the influence of weather, like sun, Ler ge ales 
wind, heavy rains, and. to. be shoveled over again before asiné. i CBR a 
After each wixing, the. platform is to be eleane@ off ‘agein be re 
“Mote 4, Ws ORS Purther Bee 8B & Be. 412i. pe ABT. 2 ne vee Sy eas 
On the transfer of the Finished concrete to the place. of use eae ie 
and the tanpangsas it, gee. Sebtion wm, an SS are Cs Se alte Ch 


Wixing with machines is. seestiasli. done’ ‘the: same. as is ATE) gape 
Por large: works ‘mixing by beating ais decidedly preferable, sice = —™” 
a wore uniform mass is optained, independently of the skill PY eae 
the .workmens 4 ‘The work of the machine ‘is also_ substantially — ew 
more reliable and is ‘simply ‘a necessity. for large works, ‘since 
thereby ‘can be saved 1/2 to 2/8 of the cost otherwise, Great oe ce gti 
machines ef 10 to 15. BP are able ‘por day of 10 hours: to produge) 70%. t 
up to 400 n° of mixed concrete, thereby considerably ‘shortening = 
tas building peried. (Pilbiag the mixing drum 30. to. re tines — Shs 
per hour, which holds 0.1 to 1.2 m9). One distinguishes feats 
fixed and portable mixing machines, ‘that are partly equipped 
with automatic. filling and ‘discharging apparatus. 3 fheir use 
is mostly very ‘simple, both for mixing as. well as for walling | 
and discharging, requiring but little labor, as. a rule. only. oa 
wan, ‘The materials, are putin with ‘shovels or mncelbarrons, 
mixed dry and finally mixed wetted. as a ‘Tule the WEL Wass is 
alse kneaded for a tine, finally to be ‘taken. by. cars: or cele 
barrows to tae place. waere. used. ‘Host frequently driven by. a 
portable steam engine set in a place ‘protected from vind nd 
weather, easih eccessible for: water and coal, ‘and waich may 
also drive other ‘building machines, “Like: band ‘says, washing 
machines, pumps, ebC., as. well as to. ‘hoist the concrete, tO. 
tae -apper stories, and also. for elevating ; 


stone, ‘timber bre et 
Tae engine in this way takes all the ‘work, that an be done 
by a machine. os For. smaller work suffices an electric motor ee 
or better a benzine motor, which is mostly cheapest in use, eM 


(antag. per spade of 10 hours and 20 ro of concrete about 40 esd 


ing wachine, oupelying materials apd “tte ee 
nan ear rab Sao (Re Least tine for spears is. ‘about 

winutes (30 to 40 revolutions).. ee (ee ee 
Kote | hets8a. The Austrian Reguletiens of ‘ie08. require a 


orgase of about 5 pecs of coment for hand wixing. | ee 
Kote peGi. The use “Of. Speotoy weasures. for. na cervals. used. As 


generally -OULVLteda. For the wsuel: water ot: at: Least ASO Vrres. 
suffice wneeloRnvons - OY. Gump lng | Corse wth known ‘COphon ity “ond 
Vhe Wike. Bor the wixing proportions . to. be senployed AS token Ea) NAESieok Some Meee 3 cd 
& certain auneer of vorrows oF gorty the. cement As | Measured An = er. ie 
B COSk wade for whe. purpose, ae SS ahs SE RE ah a ee | cup 4 ns 


Note 1.67262. Pisadvantages of porravve . engines tor auc ete 


es 62 Ea Ua Pe ieee a 
svtesz-- Spector constant attention, waintaining steam during 
pouses nr the MOrKe La Sonereal oO portable steow ‘engine wh neg 
the use of Vess than 15 H.P. &8 eeldon advantageous. ee 

NOLS Zepe 62%. An eleotrrve moter Vs. ORBVTS VY softer - An use ana 
requires the Least Ci Rishon; Pisedvantoges | are often. the quite ag 
Vaportant cost for the arrangement Of. tha electric wiring. wage o 
ALesadvantageous Vs the fact, thot Ahe .electric CUTFSWTS at com 
mand bitch lest, pary wuckh HA kine. Ons gvoltage ot the ai{ferent 
puilatag sites, One can count for 1 w Of LSLFES  GORGRARE SUPE SS 
BO pec. Of the price of current Soe che cost, thus sven: 15 to a 
20 HePe 

Note SePeS2. 100 KAY vonzine ‘outs avout 35 %o 45 waite - 

Rote AhePeSde See B & Be 1Vi2. pe AlAs \ | 

The machines a@eliver concrete with any preferred sackee, of 
WOLSture.e foe different mixtures can be furnisned ‘in exactly — 
determined Quantities and snow the most perfect uniformity. 

Fone strength of machine coperete | \(compressile or tensile resis- 


tance) is quite great, and in consequence or the thorough kne~ co 
ading of the mixture is often 20 to 40 p.c, Hieber. than the eo 


“strength of concrete obtained by hand wixing, + ‘Bor machine re 
work under some circumstances a Leaner mixture Can be sabdgei 
icn is able .to present asa strengtn \es & richer mixtore cde me 
nande Se | ¥ Ae at 
Note 1. He 63. TO obtain better eerneotor: strength, Vy ce ae 
advisable to work only CeBSRT ond Sand with worter Ato. norton, 
Laon f{irsv adarag. the crushed stone. to the Frwarisnea mortar. But 
BSually whe Aiiferent warterrars Ne placed Vn the Winer ot the 
some time, "Lovor Vs thus saved, out \ess. strength Vs obtained. 
AVsoO see Cewent. ASLA. Pe 152. 
Concrete wWixing machines may be classified as follows: == 
a. Machines working intermittently, the so-called charge 
m1lxers. - ($be- material is received and discharged successive~ 
ly, nay Be mixed longer or shorter; reliable mixing, but slower. 
Note WsyeS3. The machines wenrtioned under 1 to 4 \{ree favv- 
Lag mixers) “properly aiftfer only in the wanner of Avechargings 
i. Free falling mixers. (Simple sttendance and cheap, ‘koathy 
hand labor, but with small capacity for production). . 
Free falling mixer ‘of F.B.Gilbreth. Boston. Mass. 
Free falling mixer of W.Daum. Wiltenberg-a-li. (Pavaria).. 
Pree falling mixer of beipaig Cement Tadustey, br Gaspary 


at 


63 
and Coe (Inclined drum). 
2. Free falling mixers with vertical GPOR EME NOT TALE) mixed 
in a rotating druw and continually falling). 
Mixer of Gauhe, Gockel & Ca, Oberlannstein. 
Mixer of fobler, Borsigwalde near Berlin. 
Mixer of Beneral Architectural Machine Oe Leipzig. PE ey 
3. Bree falling mixers with a mixing ira rotating about ts ene 
@ horizontal axis (mixing shovels on internal surface of drum). ieee aren 
Ransome mixed made by Deautsch & GO.. ‘Berlin. (Drom holds: 
iz00 litres, daily product up to 320 p23). | is 7 Regetine 
4, Free falling mixers, where tne mixing drum is tipped a a 
about an axis perpendieasar to its axis of rotation for disch-— 5 
arginge 7 Bi ace Meee es ea ae : 
Swith mixer, Drais dorks, ananein-Haldnot. (Drum holds a ee 
ap to 9300 kitres, daily product feed ae 360. ~, with fone filings - eile en, 
per nour.). 7 ie 
ae 5+ Fixed hop:zentel mixing wrough with discharging valve ee et 
in bottom,(frough open at top, rotary arms on ‘horizontal shetay 
Kang mixer of Royal Bavarian Foundry, ‘Sonthofen in Algau. 
(Very productive machine, cheap and reliable: in operation). ee es 
Mixer of Wolf & Go. Gubens” peace Raa Oe age ee 
Mixer of Gauhe, Gockel & Co. Gheblesapiaias: tt, RR A aa 
6, Mixing trougas, that can ‘be discharged by rotation aboot aM alate 
their norizontal axes. (lostly witn Johitiicas arms ‘on a a verticad it er : en 
axis)e é Se Nak ae aE ; eens a ses Pr bas Weer 


re 


Hfeen mixer, naan by Beyer & Zevecne in Plauens ‘Guenans SS ae 
fixed for factory use). ae 3 as esc yea 5 tees. Pear ae 
Mill of Birich Cg. Hardheim. — ee ENevadare iota 
b. “Macnénes working continuously. Qjaterials: constently ¢ ss) Mead 
discharged at one end. and, nauseam ab the other; less reliable nc Eee Wee 
WOE Ks : Pe et ee em fc Noe fg eS | Baek Ae i, / eg 
i. Machines. wita feneenene fixed. piking treenand spit as 
ral mixing shovels, which require. the uaterials regularly: while ee a Can rhe 
the machine is ronning. ae vs ie SERN ogg pe meee ah es aes 


Mixer of Binber & Layer, _pusetldnctoeabont 68 ng iy 


oo Wachines. kids inelined sarnes srenahe Renee fing quali ise ¥ 
work). ie (open Ty Sam ag ach oer Re ae 
Mixer of. Gaune, ‘goekel: 4 Co. 0 Oberlannstein. (erosuer 4 40 ; 
to 60 we with. oat to 2 ‘BSP a Be | ‘3 


cece 


64 
cylinder. (Also gooa for small work). 
yixer of Gaune, Gockel & Co. Oberlanastein, Product as for 
Z; with bana power, 15 to 20 mn. ae | | 
Mixer of G. Hiller, Dresden. : poke eee ey iy 
Puonsl mixer of beipzie Cement Industry, Dr. Gasbary & tie. : Doak 
4. Machines wita inglined rotary ‘mixing Grum. 7 
Wixers of Anderson & Sons, Detroit; also Samelius, Rotterdam. ate 
5. Machines with rotery mixing drum, where the materials are 
continuously moved from one end to the other by snovels, Saisie | 
etc. fixed on the internal surface of the arule aes 
Mixer of M. Kraus. Munich. ce 
hép ine most appropriate choice of a mixer dirst depends on bow 
much concrete must be made nourly. Small ‘Mixers are dearer. ia. 
proportion and are not economical in use. Phe machines nention~ 
ea under 2 are interbittently working, where the arn 1s filled nae D Pesta, 
with the materials, wixed, and tne completed | wixture aiterwards oe 
discharged, are best suited for reinforced concrete work. Tne oO ee, 
reason for this is, baat one is able to continue the mixing 3 
process until the desired result is obtained. Continuous be Sr 
ers come inte consideration cnieily tor great masses: of foma~ 
ation conoreté . : ‘ | es Ses : 
Generally tne ‘ebieseon snould | be given to such acca CAS 
that agt only mix rapidly but at the same time thoroughly kne- proces ads 
ad tne concrete. ‘Phe highest resistance 1s then obtaened, which) 
advantage should decide against the disadvantage. of a somewhat 
greater driving power. Burtaer points; easy and quick. use, ipOth” cae 
in filling and discharging; ‘good regulation of the water added; PN 
no falling of materials outside, unico makes the parts. of the = 
machine dirty; least annoyance © ‘from chains. and | belts; - small a : 
weight (small cost of transportation); simple cleaning; suall 
replacement of all moving parts | i ‘(starring arms, ‘etc... inel- 
ly, 10 is also preferably under some ‘circumstances, os ‘bne wa=- as 
chine be so constructed, baat. the ee woile mixing: rem 
in visible to the workman. eee. Fe se i rR Cy eae er: 


mae We ies ot 


atone oft course sizes aareosg. ‘cones. the. “grestest: vepairs: ape 
further Veesen. she producing capacity of. whe. wochtne. aa ae 
icon: Beis eae 40: the. “usée. of mhehiaes: for cast concrete, see 5 ee ae 


ea 


ve an oxanple « ot. a wiixer is. “stoma in | age 17 a machine ae oe 
the ~ BOO ame eh ec id gOS are 


7) ae 

she Royal Bavarian Foundry at Sonthofen (system Kunz), that + 
pas been much used for 20 years for reinforced concrete struc- 
ures. i@is machine has a capacity of 150 iitres and ‘proguces © 7 
5 to & uw? per hour. It belongs to a class” a; a fixed open arun, sat 
a system of kneading by Wixing arms wita movable Mixing abbas | 
discharging tarough a valve. The process of mixing is under the. 
eyes ot the attendan& workman and the foreman. The compulsory 
tnorougnness of tne mixture shortens tae time of mixing consi- file 
derably, and increases the producing capacity of the macbine. : 
Tne machine is frequently arivenby an & H.F. benzine motor, of, 
on larger buildings by an electric motor or a. portable stean 
engine. Frequently attachea -- for buildings -- ame a concrete 
no1st. The concrete falls from ‘the Grub into a. . trough, and ce 
en passes witnout furtaer attendance, self discharging in all 
stories. [nls arrangement nas already worked to a BENDES. of 50° 
m at builaing sites. 3 | Sy 

Tne just described machine Be tae Sontnoren Foundry is boat | 
nost Common for reinforced concrete buildings. But the founary ° 
aiso builds machines of 3.5 to 25> or even 40 wu? product per 
nour, indeed with ana without lifts, as well. as with ang wita- 
ont attacned benzine or electric ROLOTS. > 

B. Mixing Proportions, Hatessete used ana Weigat of Vo~ 

lume. “i er 2 
One must Gistinguish between “rich”and : “Jean”mixing, accord- 

ng to whether less additions are made to the cement (rich. wix- 
ee or more are added to relatively less. cement (lean mixture). — 

Por tae choice of tae mixture of a concrete, ‘woich is to. be Bate 
euiployea for a definite portion of a structure, tae ‘demands are 
to be satistied, taat relate to tne ‘strengtn and: density ‘to be 
estaclished in the structure. Bat the strengta of. a Concrete 
is then naturally produced by the good qualities: of the” Paw mua~ 
terials, i.e., of tne cement, sand, ‘agercgate (erusned stone, 
gravel), as well as the water. — a 

The good properties are botn chemical as. well as che oiualy 
the former come into consideration for cement and water, the 
latter play a part in all raw materials for concrete; ‘these 
are particularly the following; tae fineness and purity of tne 
Cement, the purity and temperature of the water, — and finally ‘ 
tae crushing resistance, nardness, structure, -s$1ze and form of. 
ecrains, and nature of tne surface of the sana and of the aegre- Ae) 


66 

aggregate. | Ba piles ah: Sal 

Since then these numerous chemical and physical properties wre 
combine in the most varied groupings, and thereby way influence 
toe strength of the concrete, it is easily seen, that a numer- 
ical assumption of the mixing proportions of a concrete ot a 
reguired determinate strength is not indeed possible. 

Phe determination whether a certain concrete possesses the 
necessary compressile resistance tor a certain part.of the ba- 
1lding thus remains entirely a matter of experiment, which: is 3 
to be made in every case with great care and repeatedly. Espe- 
cially (see Section III G). Tne strengta is generally sovaneh. Se ey 
less, the- greater the. quantity of ‘segregate ang the less: tne Ce ome 
content of cement. ae Oe Ne 

It is even frequently mixed too ik pitiupehociy tor great Pan Big e e 
masses, like foundations, retaining walls, BUC. Sven very dean ol ee 
concrete is better and stronger against compression and ‘tension | eh athe 
than the best masonry in lime mortar. No fixed ‘mixing proport- ne 

Lons should be prescribed beforehand, ‘but only definite/stren- 
‘gth is required wita a definite factor of safety. + By consci~ 
entious selection of une materials. equal strength way be obta~ Pes 
ined by leaner mixtures, thas. by :: ‘capricious noice with con= ay 
siderable richer mixtures. Per is: ee . i 

Kote 1. Pe 68. Bor example, o prescribed mixture. of is cieaee 


* 2 gona + 5 crushed. stone: Vs. ony. 4% be: negarded os. weswle, ; ; 
when Wa the d- parte. Ot eruehed stone. As found - ot Neder 35 Peo ee es 
as stone chips 7. to. 25 wn: aoe ducal aS ay ae ne ae eS 

{ne wixing proportions: usual. in: practice, ‘and mest Geonrenie 
atly numerical, are not always those’ most favorable to economy, 
and naturally ean make ‘BO claim to pertecy density of he econ 
crete. Rk AOE ie Sh pute Her eek OAC ted | 
Tne future density of the te A is. ensured, ad ‘232 Rate Oe ee 
ities existing in’ the aggregate ate filled by See ae ue 
waterial), and thus the cementing material ibself is dense, dete | 
all crevices: in the mortar: sand are filled by cement. By ‘the 
representation an Fig. 18, abas evident, chow such a definite 
quantity. of contrete ais composed. of cement, sand and eruaned — 
Oech cement and ‘sand particulerly serve. to. fill one. erevices” 
‘Of the aggregate. 3. Tne density of a: ‘concrete. or. of 8 mortar Sg 
Can generally be ee Be foe eae ° 


sete eer sree ere re: 


OREVAGOR:: . 


Bye SOR 
3 ibe 


| 67 : 
NOte Ae Ye S85 The Gensity plays a great part An certain bu- 
VVaings, for example in water Teservotve, vunnels wander Sicha 
etoe, OU POrticuLarly for reinforced. Concrete structures, and 
yadecd Va reference to protegtrvon of. the ‘velaforcement from diate 
tn wost sands ta use the Vinit of denerry of the wortar Xs 
gvoey Ly about the Wixture 1:5. | : 
Note 3. poge. 68. Attention shoulda be called. abuse. to. the foot, 
that Vadeed the Bost common procedure of Bererwibing | the cavi- | 
ties dy TVLVAng with water ts not. entirely free from. objections; ae 
os a rule i% gives too sual values on account Of GLY Buddies) oo. os = 
thot adhere to the sand examined. It. Vs. softer. to obtain the & : ae 
volume of crevices from the voluue WEVBRT of. the ‘sana. (shaken 
down stroangy ) (ond. the epecific. gravity - aK: whe > sane (averaging 
2.65). j 
Im a loose Bass ore Contained crevices: -~ , | e 
In cement avout 52. pec5 Be an | Hee oe ee irre 
‘Im sand about 80 to 35 pec. nah He PIN ERE A. | 0 Se ait 
Ta gravel about 25 to 40 PeSe ? ‘po - 
‘In crushed stone avout 40 to 50 Bets LA axak Var eaaition - 
of crushed stone, “then! Less product and. BSATe” - -ooncrete). Pie ee 
if ail erevices are exactly fiiled witn the morbar, numerator nN 
and denominator of the expression for d are equal, and one ‘sp- ee 
eaks of & mortar or concrete with the density a = =i. Hence & Rome a eo 
mass is not dense, if the amount of crevices exceeds. the amount nee 
of mortar existing. Oe | See a ee Pig 
Practically, in order to be wake and to avoid. tae dip eak hes Peg ee 
tact of pieces of agéregate, care is taken. to. give the mortar <) pot eMe yet 
a certain excess beyond the quentity required for qd = i, and eee OL ae 
this excess amounts to about 15 p.c., i-€., one uses 1. 415 Roe en se 
es the quantity ‘of mortar, that would produce dense concrete, oe oe i 
thus obtaining a concrete wita the density ad = 1.15, wnere all Ye See ea 
pieces of aggregate are coated by a layer of mortar, Sb gneke ay < 
It is usual to indicate concrete mixtures by tne fora:-- 4S ake 
wn, for example 1:3:5, tais denoting phat. the mixture GOnsEBtS 0 es 
of i cement + 3 sand + 5 aggregate (crushed stone, etc.) . Wita nN Ser aie 
the use of gravel sand, i. e., gravel containing sand in the pro- co wee Ne 
per proportions, one writes i:m, for example, eo uae The parte he eta 
of the Gifferent materials are given in voipmes (litres). The oy ere 
proposal to mix by weight ab tne building site (as usual and- ae ttt. 
proper in laboratories), can onky. be. agreed. to > conditionally, ha ee sy wees ier" 


03 
as well as the aecdesi ties to, measure the cement. by weignt and | 
the additions by volume. The volume weight of the aggregate Poe 
yeries with 1%s iineral ‘Composition, and atcording to 1ts act- arin 
val content of water, and the volume weight or the cement res is 2 
ording to tse degree of snaking together . ‘Different volume = 
“feignts of the cement (see p. 68) would lead to considerable > 
irregularities. fne following weights may serve for calculations. 3 
Sand 1500 kil/m of a loose MAES. eet. eee Ake Male 
Coarse gravel 1550/m3 of a loose Ry en 
Fine gravel 1570 kil /m? of a loose mas SEN eee | 
Goarse crushed stone 1300 kil/m? of a a Mass. see ae 
Fine crushed stone 1320 ‘kil/? of 8 lobas MENBa has 8 or 
Portland cement poured. 100 to 120 averaging 420) kil /#00 ee: 
Portland cemént snaken. 160 to 210 (aver. 190) ‘ki1/400. litres. 
Portland cement filled 110 to 190° (aver. 425) k11/400. ‘litres. 


Note 1. Pe 89- In a given case for grad Y sana, %% wust be Lae 


tReet og 


Betermined ay a\eting. 4eat what! proportion extere, between sand i AOE 
and gravel, (aise. ‘see. Re AA) : Cee ae on 
Kote 1. Qe 1. 80 for. as. the ecasunenent of couent, by volwwe ; 
OGOurs, “Vt > is assumed. that wVLROUt . Fovving, cue cement | A Nee 
ed nto the measure | (nor shoken dounh. To ‘compute. whe wolune — 
{rom the average wergne of Portvend cement, this | way ‘be. taken. 


at 1400 ‘AV\O®, A yee bag sc Oa Se Ne Re nS A ge pone ee ees 


The statement of the couent odded ‘Sy: parks: ~ wel ght moe hom, 


ever been Vacreasingly adopted » An recent vines, especially Se ee 
France, South Germany ORG Switzerland. thus. whe Guise Reguvat- 
VOns sayr-- Varv. 43)i- ‘The CONSKETS ‘AS. to ‘be Bixed An parts. ae ee 
by meVant for Bortland cement, ond Vn porte. by Seales for sues “ 
ve\ and sand, for waking | Sioacoasts, concrete. For. a we of mixed | | } 
Sraved ond BSOnd, Vee, for Qe 8n° gravel and. Oe ce a Heese As Sy 
te be used 300 KVL. PovtVand. oemente ayes at . tae 
-Materiais aged ‘tor e sacks. | Weverials for. 1 Peonoretes 
zx. Cem. ‘Band. Grav. ‘Ston. Prod. ey ‘Stone. | oe 
1:23 2, 50 «145 oo 2 Kk. £750 


liai4 we 8 | 4290° : : 2350 285 a, 

4332405 4, «2d one 35 +430 234.500 

1: 3:0 it - 02k5 f 430 | 4 0499) 282° 435 : 
13213 2,56676165 | --- 2-530 Bane. ss above. 
Haid 5 AhS I mo ee 
4133:435 5, 0245 whe 492 0370.49 Santi ae 

BS Seo ees 1746 S432. Boag ee : 


iy 


deh 
nae 
Oy oe aaa 


69 | 3 | 

KOVe Ze Pol. MProduct™ta the Fatto of volune of the finished 
concrete Bass to the sun. of Ane volunes Of. +he components. Sen- 
eralvy the product way be essuned BN: 10: vo 13D PeGe Of. the wWOss. 
7) the COMPONENTS. Dae ce , 

if a concrete wita definite mixing proportions can be recog- 
nizea by thorough experiments as corresponding to. ‘the require- dies 
nents of an existing special structural Case, them is debi hte” 
for estimating and obtaining the raw materials e knowledge of 
voce required different materials for a unit volume of connate 
ed bearing concrete (1 nm), cement, sand, aggregate (gravel, 
crushed stone, etc.). It is generally. advisable to take the x 
vobume of gravel or crushed stone about twice as great as taat 
of sand, assuming that’ 'tais refers to grains of different Siz-— 
es. Bub if the crushed stone (especially that made by ana) :. 
nas quitke uniform sizes of grains, tnen tae voluue of crusned 
stone is taken only i 1/@ times tae volume of sand. In the Ta-" 
bbe on pe /O are given for both cases” tne volumes of materials 
ior a wixture wita 2 sacks of cement. a 7 : 3 

Note Le pe The AVso. SSe Table ON YP. Tas ve Vane 20° ee 
to be used here, : 

Hor example, if for a bullding a total ot 250 Pee ot ‘concrete. 
is to bce mixed 1:3:6, then come in Anes tion the volumes of the 
differént materials. — | 

Cement = 250 x .202 kil = 50,500 kale 

Sand = 250 * 0.435 mu? = Bie) n>. 

Gravel or mixed crushed stone = 250 x O. 370 + = 218 a | 

in the following Table is g1ven for usex of a gravel sand o : 
wixture |. Cement + sand and gravel(i:2).+ wate materials for 


Mix. ° . proauces in tamped concrete ad 1 we gee 

| Ae ec Celi. ‘kil Sand. 

. a a4 ee ce gravel. oN ee 

ii 50 k.# 501 +421 = 541925 Oyeey 
1:z 50 k + 7Z1+13 15 & «83 1625 0. 866 a : 
1:3 50 k 440814451 442.1450. 40.9647 
i:4 50 1 +444 1+ 18.61 = Pia al BASS AE Ogden 
i550 1+ 160 1+ 22.2 1 = & S490: E299 A059 
2:6 50 1.4 216 1.+ 25.8 1.= BOO 1 e5Gt + LBBGS OF, 
1:7 50 1 + 2521+ 29.41 = 290.1 220".4.091 * 
4:3 50.1.4 264 1.435.012 = 3 263 Lie 1.095 > 
1:9 50 1+ 324.2 4 36.61% (2961 109 «1.094 — 
1:10 5014+ 50014 40.215 ° 330 1 15 


454 4.991 


rae “50k + 59614481 = 
1 i2 20 k. + 434: 1 fs Aja) * = 
Beg a. Re Tie For ateing 3 4 ; 
On average. value. ae 


or reinforced concrete (noses, 


wi bo 


Liha bak 4a 


per ey is. officially ecole: 


IESG 


of tae. concrete in | reinforced ‘conere 


ee 


, aie yi 


will be esroualy affected. oy rai eee 


4 ¥ aly Oe ey wr ee 


ed to the proportions occurring in precties. nee : 
basis of tne foblowing considerations: ~ - According to ni exp 
erience the specialist knows ‘by tne use of ‘he. different ager 
egates approximately, with what p. c, loss. 20 ‘tauping ‘be must 
reckon. One can generally count 4 ren of finished concrete as 
requiring 1.3 to iy a? of materials. ByD loss. ‘as. ‘to be under- 
stood the sum of tne amounts: by which tne loose. mass: shrinks — 
in wixing by filling tae. existing erevic: S$ and by” tae, ‘Seupiag. 
it 1s mere to be. assuned, ‘baat the aamns entirely. disappears — 
in the volas, thus naving no effect on tae later total volune. 
for example, if ode uixes 5: Pe wita Cs em Cexent, ‘baen the ‘nized — Se Uae a 
and tamped mass does not amount: to 6 mw, bat. only to. about 45. HO es 


to 5.0 m9, Agama designate tae mixing proportions by ‘dima and a 


re 


the pec. of sarinkage by 9, then for ae a of bamped concrete | 
are required the quantity: of uaterials as follows. Rae 
Note 4. Pe72%. Soe Ritsche, ‘SYotervan Requires: “ond: ‘Density, oo He ee 
Concrete Mixture, OSsuMVng that the | Aggregate: con, ve. ‘Asipea. ai? ee Po ae a ae 
Logethner.” 1 | es De Crnmtiy Mee eco ag oe = pee oN alg 
Pein ae Fi i 
‘" £0r the usual concrete mixteres baé shrinkage amounts 40. 15 ; 


tO 25 p.c.; thus © lies between 0.15 and 0.25: . For example, eh 
tor i w® concrete, $22.5; 5, with @ = 0.15 would be required, 


1 1 
Mo 2 perrt tm ter esr enin, = tece = 0.157 m® cement. 
My = 6.5 x 0.157 = = 0.9593 mw? sand. 
ie = 5 * 9.157 = = 0.735 w* aggregate. 


Gravel sand sarinks léss in tamping whan crushed stone or PS} 
sravej, when separate pefore mixing. wor gravel sand wixtures, 
ons may count. on @ shrinkage of 18 to gb p.c.:for Sseparaisly 
added gravel or crushed stone, co to sO p.c. 
Mixture.  @ # 0.30 o= 0.26 \@ = 0.20 
Liuwin. Gem. Sand awlCem’S'a” AvelCem $a’ A ) 
& 


& . 
tii: 714 714 714 667 867 G67’ 625 625 625/588 538g 58. 
* 145 591 571 857 533 533 806 500 500 756 4717471 707 ."* 
zZ 476 476 952 444 444 688 417 417 634 592 392 764 ° 
2.5 408 4081020 361 361 953 357 357 893 336 336 840 
36 357 3571071 333 333 999 313 313 939 294 294 882 
30) © ZB 3171110 296 2901036 278 278 973 261 261 914 
2:1.5:1.5 476 714 714 444 666 606 417 626 626 392 588 558 
408 612 816 381 572 762 357 536 714 336 354 672 
si e i oe. 


565 286 4291001 267 401 935 250 375 875 23 
260 3901040 24 
i; 2:2 357 714 714 33 
2.5 317 634 793 29 
3-286 572 65S 267 ; 
3.5 260 520 910 242 484 847 227 454 795 214 426 749 
4 236 476 952 222 444 885 208 416 832 196 392 784 
4.5 220 440 990 2 23 192 364 364 181 362 815 
1:2,512.5 286 715 745.2 68.250°625 625 235 588986 4 oS 
3. 260 650 780 242 6 6 227 568 664 214 535 642-5 
305 238 595+833 222 555 777 208 520 725 196 490 660 . 
4 220 550 880 205 5 0 19% 460 765 181.453 724 
4.5 204 510 918 191 478 600 179 448 606 1668 420 756 
5 490 475 950 178 445 890 167 418 835 157 393.785 
238 714 714 222 666 666 524 624 \é ni 
220 660-770 205 615 718.192 576 672 181 543 634000 
204 612 816 191 573 764 179 537 716 168 504 6720 


f< 
ON © 
fo NT WS 
oO 
& 


ze 

we 

mm Ww 
wr 


-5 190 570 85 178 534 601 167 501 752 257 471 707, 
5 «179 537 695 167 501835 156 465 760 167 441.7550 
Pre) 


168 504 924 157 471 864 147 441. 


oa hee tre 


Atay ok 


2 


Ss 


326 159 477 954 148 444 865 139 417 834 131 393 786 
13.5:3-5 204 704 714 191 669 669 179 627 627 168 588 586 
4 190 665 760 178 623 712 167 585 668 i157 550 628 
4.5 179 627 806 167 585 752 156 546 702 147 515 662 
> 468 586 840 157 550 785 147 515 735 136 483 690 : 
305 159 557 875 148 518 814 139 487 705 131 459 721 
@ 150 525 875 148 518 814 139 487 705 £31 459 721 
(7 136 BO 952 127 445 889 119 417 833 112 392 784. 
1:4:4.5 168 672 756 157 628 707 147 588 662 138 552 621 
4 179 716 716 167 668 6608 156 624 624 147 588 588 
y) 159 636 795 148 592 740 139 556 695 131 524 655 
5-5 150 600 825 140 500 770 132 528 726 124 496 682 
6 143 572 858 133 532 798 125 500 750 118 472 708 
6.5 136 544 884 127 508 826 119 476 774 112-448 728 
7 130 520 910 121 484 647 114 456 798 107 428 749 
S 119-476 952 111 444 885 104 416 832 96 392 784 ( 
4:535 143 715 715 133 665 065 125 625 625 116 590 590 
§.% 130 650 780 121 605 726 114 570 684 107 535 642 
7 119 595 833 411 555 777 104 520 728 98 450 680 
7.5 144 570 855 107 535 803 100 500 750 94 470 Go5 | 
8. 110 550 880 103 515 524 90 480 766 906 450 720 
g 102 510 918 95 475 855 689 445 801 84 420 756 
10 95 475. 950 89 445 890 63 425 830 98390780 4 
1: 6:6 119 714 714 111 666 666 104 624 624 98 586 566. 2 
7 110 660 770 103 618 721 96 576 672 90 540 630 
8 102 612 816 $5 570 760 89 534 712 84 504 673 
5 95 57956590 555 89 $98 890 98 468 727 7a ada 7oq 
10 8G 534 890 83 498 830 776 465 760 74444 740 
14 84 504 924 78 468 858 74 444 S14 69 414.759 
12 79 474 945 74 444 888 70 420 640 65 390760 ae a a 
by 3 102 714 714 95 665 665 69 623 623 845868 588 st 
8 95 655 760 89 623 712 85 581 664 785466240 
g 89 623 801 83 581 747 78 546 702. 7h SER OOO 
10 &4 568 840 76 546 750 74518 740 69 463690 
ii 79°59 869 “74 546 614670: 490 770765 455° 715 
12-75 525 900 70 490 840 66 462 792 62436744 
13838 89 712 712 6&3 004 664 76 624 624 74592592 ne 
g 84 642 756 76 624 702 74 592 666 69552621 chy 
19 79 632 790 74 592 790 70.560 700 65520 60.5 2 
id 75 600 825 70 560 770 66 528 726 62496 682002 ee 


: Ty, ee 
PT fable: just given toe 73s 74) contains ta 


quired for a great series of mixing: seen fe the. = ate 
@ = 0.90, 0425, 0-20, 0416. 


Busing be Scnuuann. Portland Genent ~ a in | 


eae on. ‘saagitges and ‘on tae water ‘added: less igre 27 
nuTADG, Prppersipats: eae is an ‘general amigher, we Besse 


a greater volume weight on ) account of ‘she. OY Sapein 
taan would ‘correspond to. une concrete of has: stesesure ae 1 
CONCErned. | io eee ; 3 : nN aek rs : eee 
Note Be Pe 13. Bor ‘pumice Ong oinder concrete too analy eke, te mee 
wes are mostly given, one hos een eatavlished polume weiants A ANS AOS Tete 
of 1500 to 1700 kiv\m® for these Winds of concrete. The ruses 
Von Beguvations - on Voods. wo be employed for wuLvaings | (isto, ve 


Jan. 31) give only. 4000. we? OS average values” (eee wigaincee ae 
wWHiGH Con always be. taken for {ULVAng purposes, oe anes) . 

Note 4. Bp. Td gor oratnary trenen concrete bout the Youou- ‘ ho, 
Vag values are. vo. be taken. ee) ear ee iy a a we Dat Poor 
Wieture | ARB Os Se - eae Chrno a als 
Vove Kt. in weit saonyaaeel aaah Lowel 2440) Rone Oe ee 

One may usually compute wath tae following values: -— eee soe 
Cement + gravel (gravel sand) 2200 to 2300449 2200 avers Hit Saas fe on 
Cement + crush. gRManite — ZQ00 EEO Z500 > se SOO Mi > cree, Ge oe meee 
Cement + basalt crushed — 2200 to 2300 ~ 2400 4, 7 | | 
Cement + lime or sandstone nee 280 
Cement + crush. bricks 4500 te 2000 =. :-1800,, - , 

Cement + pumice gravel LO00to 1000 1300 re ie 
Cement + coal cinders oi BOO: 4a 4560 1200 TN 


On Volice werghis of aif Conckle, see Seotvon Vi ¢ L 


74 
p.>6, Os Wooden Forms and Centering. 

Hor the purpose of concrete work is first to be arranged a 
woode@ centering, that causes considerable expense to tae con- 
tractor executing the work. For wdod is in itself a comparati-~ 
vely dear building material; furtner by cutting and using,1t 
is injured more than 1s tae case for working scaffolds and. cea- 
terings for masonry structures. + Farthermore a great portion 
is always lost Guring the building, since stealing of Some lug- 
ber 1s scarcely to be prevented. For simple structural forms 
the cost of forms amounts to 10 to 20 p.c., but for large puil-~ 
dings often to 50 pec. and more of tne entire cost of the puil- 
Ging. By proper and skilful’ uSing again tae lumber on tne buil- 
Ging site,the work of Toes may be cheapened. A circular saw 
ariven by power can be of great advantage in tne construction’ 
of tne forus for reinforced concrete construction, especially. 
if this circular saw is driven by the sawe motor as the concr- 
ete mixer Or the existing structural acist. * ; 

Mote 1. 76. After veingd used several times, the Vunboer ext 
AGS the walue of fuel. With round poles One Can. count On weing 
10 times Van favorable cond\ tions, as sheathing boards: for plane 
floors 4 times, or 5 times for walls. | ney 2 

An important American Contracting Co. toe, 
Construction proceeds as follows, in order to spend as little. 
money as possible for its forms tor tawping:-- it has prepared 
from the centerings of those buildings, that it has. executed 
With the best results, models at 1/6 naturai $1z¢, which serve 
tor instructing its oificers. finen tne Co. undertakes a new s_ 
building, it also has a wodel constructed for tne centering = 
for valiping, Tor walch are utilized all previous e experieg§ces,- 
and 1ts officers and workmen are required to careiuily exaling 

ey His wodel and to make suggestions for simpliiying or cneapen- 
ing 1t. These suggestions are thorougnly tested for their usa- | 
Cility and are rewarded by prizés in favorable casgs. The Gas: 
tous best utilizes the knowledge its officials have acquired 
ln otner construction companies. | nit’ 

to save cost of centering an estimate is also wade See the 
Gntire building -- or at least for two Stories ~- taking the 
Same sizes of piers, dimensions of beams and vaults. In this 
Way the completed wooden centering can be used several times. - 
ta tae lowest story tae dimensions of the supports and beams . 


7) 
must naturally be as smali as possible. The apeated amount of 
steel taereby used in tne lower,ana of concrete in the upper 
stories is agaln compensated by the possibility of using tne 
same centering several times. +-- One snould at least consider : 
tne avoiding of all small differences in the girders and supp- 
orts of a floor, already in the design. 

Nove LePe77. LV always appears questionoole, whether in rap- 
VG working, the timbers witli alwoys be used again Va the corr- 
ect places Vn the upper story. If one Gesives to produce actu- 
aL Savings, G particularly careful oversvgnt Va necessary. if 

Also attention is to be called here to this, that wita tne 
existence of SO much Centering ana form lumber a fire Way ab 
easily break out, wnich way have the most important effect on. 
the insufficiently hardened concrete. The Vienna city Cuileing 
office taerertore only permits electric lignts for artificial 
iignting, ana requires taat benzine motors and smitnos’ fires 
bé placea outside the building, aii wood rubbish to be coliec- 
tea auring tae process of building, and removed daily from the 
structure. Also see “Burning of a reintorcea concrete ptracture:: 
on centering.” Arm. B. 1911. De 205. 

Hor extensive works, where similar structural parts frequent- 
ly occur (for example, floors, ribs), one can previously make | 
in the wording yard great panels, form boxes, ctc., that can 
be used over again, and thus substantially reduce the work of 
preparation. Naturally must the ‘centering always be so connec- Mee ee 
ted together, that easy removal of the side parts is possible, a ae 
Ser frequently repeated structural parts: are often employed Pe sh | 

on forus, + especially for such parts as are made in the face ie 
tory. (Vasintini, Siegwart systems, ‘€tCe). Bolt holes” and the : 3 le 
like are to be formed by gypsum or wooden pins, tat can be a 
drawn out @ few agurs after tamping, = eee ay xe 

Hote 1.9.78, Advantoies of Vron {orus:-- use ee many ‘vines, ae nee 
{iweproof, wore rapid removal of. Torna, production of eucoth a ate 
concrete surfccee, Burther see B & Be 1942. Mabe PO cue 

fac forms must nave sufficient: strength and ‘supporting capa 
City to be able to support the shocks: of ‘tbamping as well as. t 
the weignt of the concrete and er ‘the lagorers: without tue ape aS Cetge ea 
pearance of any Ghange in snape. * One counts for forms, reagte Pate a 
ding to whether the architectural wenbers are light or yang Rice CO ee 
3 to i i/@ times ‘ne. mengnt of ine ‘conspete.. in @ ‘given: bec 


oe) Se eee 


a us Cs, UL ee . 
bey Fie EAE aS 

wa ae ev Pe i x 
25 Se SA , . 


ee AN 


gnt of the concrete, fhe fixing of tne forms must present as 
livtle difficulty in bandking as the. removal; an’ ‘interchang me 
‘of the: entering planks. ‘must proceed easily: and ‘conveniently.. 
The: use or bape! is. byte Limited ea geste a jy es 


centering to ‘equalize tae ee ere 


v2) 
‘ 


a peelisanary y sponing and pepe 


1f please: 


a Othe 


pane mula). the ht ae» 


eh 
r sibel 


| etaee a Te As qo ealin ly see 
Vocal to Rave ‘he. plans for. toa en tne the ise Wear ; nee 
ored by the supervising ‘end ineer, RG ae Se) : me 
The sheathing planks. usually have patedlel edges. as. § left by 
the saw, are sufficiently thick (3 to. 6. om), 1 and are to be. Dots 
firmly Jj@ined, so that by tamping no splits and. “above all ae ee 
deflections occur. Mostly pine bauber is used, indeed in leng- 
ths of 4. to Gump ‘Shorter Planks” are obtained: by” cutting. Blenks 
previously used. for forms must navurally be, cleaned off. Before 
the placing of tae Concrete, thea. ‘the complgted forms: are-to 
be Cleared trom the wooden pieces, sawdust, {dirt and the like, | 
are to be well wetted, SO ‘that the ary wood shall not absorb 
trom tne concrete theiwater necessary, for setting. : Be Rrert 
NOLS. 100679. THAD, boards Bust be wore: Frequently supportea. ues 
waich requires ‘wore. Auabver for aupporte and more WALES o' For re ye 
s\aple plane floors. already suf { ice. planks 33 wa thick, for Oe a 
architectural forus WHER mush cutting, ‘VX NS best to. take voe- “ 
Yas gbout 26 ww tek, for iivders ‘planks about 3 ow thick. | | 3 ae 
(5 * 15 om). The thicker the \uaber, the firmer and wore resie- Be ER AR 


by outtinge Ra saith ASS at oY a as ids ov 

Tne centering is usually close. jointed, ‘since - the ‘exietence 
of too open joints” is at once noviceable on the “smooth surface 
of the concrete, ‘But. on tag other hand is to be taken into ace 
count tae Springing and gt aed of. the ‘planks in consequence ; 
of the effect of the wet conarete mass. ‘Pherefore eee, ‘is. advis 
able, . especially for great surfaces, to arrange for open” joints: 


4a 


up to a CL wide. po ak ‘the gpeverieg Leglanten Peapcepaty: 


¢ 


ra tt Se a 
"ial ; ey * 


Yote ee 196. warehed aoney cones. into. 2 eonesderacion te 
wet concrete. (Gast concrete), iSee ps &@lon cr ae ie 
For supporting tae ‘gentering for. tae ‘slabs and beans” on tne 
floors or ground Beneath serve strats. (cimbers, posts), Bae 
whimh are necessarily to be 80 | arranged,: Bhat tas ‘censering,® 


ter tne setting of the wet. concrete, fa their use again at: 2 
other places, anile the eatery are necessary tor ae time to 
support the entire centering. ig eee oe ‘ 

Note Lepe80, See Seethon: | aNe ae ss 


proper shape, and these are’ to. bee oacatiily’ ‘qatoaed aude ae 2 
concreting work. een set on tae. ‘ground (celiar story) a ‘sutfi- EF 
ciently large block is to be ‘placed’ under the wedge to distri- co 
bute tac pressure. * Generally, one counts: about hs Strut to e 
each mot floor area, for a strong plank Genteringya strut to 
2 u*, for wooden or iron box forms a strut to.3 u* or more of 
floor area. Usually round logs of & to 15° Ch diameter are tak- 
» (Mostly 10° or 12 cm diameter). Squared. timbers (8 x 6 Cm 

to 14 x 14 cm) are seldom employed on account of ‘the higner ae 
cost. Long struts must have greater diaueters on account of a 
the danger of buckling; otherwise bracing both. “ways, woicn is 
always proper, is here certainly necessary. ait "ee eee 

Rote 2.p.80. The wed Gh ive vee see ee 


. 


-o 
me 


78 

to the pa BWBLUTS Of whe ground. The pope aoy ke wetted i, 
the worter used an concreting, mMALCh moy result In the ovnking 
of the Tramework. 

for the supports must be haniacek waole Bimbers if junk: a 
if a single splice be unavoidable, then must the struts be ne. 
curely and firmly connected ‘together at the joints. 3 Simple 
bolted joints are “not always — to be. recommended, and steel tubes. 


fnere are various patented arrangements for adjustable struts, 
that make possible rapid and simple handling, Phe Fix strat = 
holder, is “ilvestrated : in baa and arregenent | in Bie. 2. eer 


ve braced woth. aayee™ pig Mute alay 
3 Ro Be >. set é 


NOUS Leb. She On an nse ata of 


Medes * 


in ig. 2, ‘or ase »ssoporting trusses | as see 


ews and. the ‘like. It ‘ene franenork: 1s. expaaed: Toor 
of storms, then naturally parvaculer sohynnohe — 


Small wriangulat wood. atrips 3 5 om in aad on: giase’ ‘are 
used, that can be. rapidly cut oat with ‘the circalar eS 
if after tne hardening of the. conerete, at, receives: nO phase 
tering, then the sides of ‘phe planks: coming 12° contact. with: at 
are to be planed smooth. Phen. only lumber. free fron. knots is 


to be used, or places with imots: are to be “smeared | with éypsune Pes 


ee 5 if * 
oGt .* oe . . 4 * ipo 


slipped over each otser & are. only used for very frequent use. er 


Sati se STea Ce ee a ae ver Bice Seats ; 
fo make igolsttie ntcnk: jointing of ‘the plantas At paffices to " 
plane taeir edges. Besides to prevent the concrete from sbick- Hear vay 
ing and 42 imprint of the grain of the wood in all cases, ‘i Cee oe wee 
frequently recommended tO Coat the planed sides of the play. ee 
the either with mineral oil, soap, whiting (ia thin paste} or : 
wilk of lime (also shellac), or to place an. intermediate capes 
of paper, felt er cloth. By coating wits soap, the pores of tne Panga ce” 
wood are filled. A coating of vhick | gi On Lan wetting tne Nes o ee re 
wood, 1 ond in this way makes it na etal sneets - i act Nae AEG ie aon a as 
even Zincked iron, are. mot properly advisable, since it ‘28: ‘hee S 
noBeEnes to avoid oulges in woe sheets. Yet no ‘sufficient seo- 
ufity is. required for a perfectly swootna and plane surface of ss 
tne concrete; the means mentioned alsq. make more difficult and — 
costly tne woré of concreting in 4 relatively niga degree. An 
application of plaster afterwards way be preferable in meny @ 
cases, at least: in the domain of buildings. = Naturally planing © 
oi tae planks yf unnecessary bnen, Since tas rouga and uneven — 
surface of tne concrete she ‘is best. suited for the. firm a. 
adnesion of the plastering, ? | 
Note 1.4.82. Good veaulis are aso. nebo lued with, ‘Site paper 


LS te 


‘sacked on. (Extra cost avout 0.2 wark\m of surface. Just as 
2004 service results {row pointing, the surface of the planks 
with a mixture of 4 Vanseed. OL + 8 petroleum, | 

MNOCS Behe Bee Soe Secrtrvon eng, Fe 

NOtS|? Beppe B®. Yet in this respect bad expertences hove already 
COCCUrTed, SSPeOVally for structaral WEwWoers @XPOSSG to consid 
erable wvVorations and shocks: -- the Paster ing WOrtar partLabby 
{vokes off, whereby. the entire structure ‘\ooks worse, than NVM 
Vi had renaaned WiLtLHowt prostering. — 

Two metaods should bé wentioned, unat may — aptly make possi- 
dle an avoidance of toe ‘quite s ? ¥e forms for reinforced 
concrete structures. Firse some aventions' have the aim of tam 
Ping on the level ground palreaay before thelr proper pse » the 
Supporting structural members, particularly columns and beams, 
in order to set them in their, proper places after the expirat- 
lon of some weeks. Tney will: then give a strong and suitabie 
shppert to the necessary centerings for walis and floors. Such . 
4 nethod of working reauces in a niga degresetne cost of a re~ 
‘laforced concrete strucbure, and allows it to be Continued at 
any season of toe year, but it excludes the previously intimate — 


80 z 

connection ef the different members completed at aiefereey tis 

ies. A previous construction of these appears to be only poss- 
ible, if in statical respects taey have nothing in common Rite ce cae 
the adjaceat walls and floors. The disadvantgges of this meth- : 
od of working. can “scarcely outweigh the. advantages | Of it. -—- 3S ar cei 
the possibility ot a very. rapid construction of ‘the ‘building, Be 
and the easy testing: of ‘tne completed ‘members: in the workshop, Re : 
The second method for simplifying the centering is to give (ia PUR Gaede ee 
the framework - of the centering the form of a self-supporting | ae Pr ORT 
structure. Phe boards and. planks. are ‘suspended from the steel Sy oe 
skeleton, that must be made correspondingly strong, and” ‘there 
by the number ‘of supports otherwise required are. essentially 
reduced, sometimes to mone. * ‘Advantageous ‘48: phen such a pro~ 
cedure, if no sufficigent: space exists: for’a onstruction pty 
a framework . for bhe » centering. ‘Yeu it may be so far objection 
able, since. bhe solid. enclosure. of the steel by the wet conor 
ete then ocours, ‘when ‘At: suffers. ‘notable Geflections: by ‘phe 
load of the suspended centering. Tf) tne steel members iare to 
be so strongly” dimensioned, ‘that such deflections are excluded 
then would: the danger result, of anekind: tae pectic x 


endioular to fibres showed. ona. o re ae ‘Hoa veda ea S 
found a resistance of 2a). ‘kil/en*. On whe ground of such resu- 
lts was employed tor struts: German oak, but. for. different ROO~ 23 
den lintels and sills” lying ‘ab the. ‘tops 2 and bases of these oer 
ruts was used. Australian’ Yoa wood. me ae Pines one Seer 
Further see the loading experiments sinilisbien’ Puakewouke Era Se 
ade for tne falsework of the Sitter Bridge (near, pe Gali) on. Magee PORN cs : 
“Lake Gonstance~Toggenbarg Ratlaeyy opteey: Gonstruction? aes ae 


Mas 


4 : hy "te re “ry £4 ty Bt eS Wy TO gt a \ eet a a A teers Vy + ar Toss SP eS 
oS AA ah a #4 Toad teas ms Re he mA 4 fthth. oat . : Les WG oe es Percy Sree sae 
r 5 H : . ore “ “ Pan) Ava pe Je Siig es : “Sy oe ea f » Psy ae SON HES igs 
acy GR $ r Cote’ ae Sy a Ne fal» so Meret Tea a y at 
: . ‘ 4 7 ii Soe Soh? z > 4 
x Pi , 5 De yh : Nae kit ty S. 7 ‘cee f hi 


“i 
pepe: b3 
se : 


to ae a 61 ees eee ee ern, oe 
pe 419. ioe hbal for. ‘Deep Construction” . “1912. Be 88. ee ae 
; Ia the following will be given some examples: of centerings — ean 

tor floors, piers and walls. Res eee PAD Mes foe fa lie Noa 
i. Centerings for Slabs. _ Se cea ey er a aig og 
For the construction of floors” between Irbeaus, it first de~ 23 ean tae eT. 
pends on whether the floor rests on “the top or bottom flanges staal BAS ee ice 
so far as concerns tne centering, Bor ‘bhe first case mentioned Aor fs 
it cts: simplest to place the supporting beams. of the centering oe 
planks on tne lower flanges, as shown in Fig. a5 ‘The planks: Oe 
are > to 4.cm thick. It is advisable. sok Reavis wedges, between 2 
the loner flange and the bysceias | | | ee ae 


by twisted duitestac clasps, as in Pig. 23, } ; _ 

Safer is the suspension of the centering by special. Seaperas. 
woich likewise rest on the bottom flange, as Fige 34 shows. ne 
Flat bars set on edge receive tne load and are secured by wea- a 
‘ses from displacement. If the flat bars are sufficiently long, fae ; 
taey can be used for different floor Spans. eet Bere ee aii be 

In Fig. 26 is shown a nanger, shat can be screwed up from be~ oe, 
low. For small spans the centering lies directly on the suppo- 
rting beams; for larger spans of the centering separate trans- 
verse beams are necessary. The removal of the centering ‘follows: 
toe loosening of tae nuts. The hangers are to be well greased Meee 
or soaped, so that they can be readily drawn out. A similar ere he eae 
rangement to be screwed up from above is shown tby fig, 25. @ uke 
(Preferable). 3 i , 

Figs 27 illustrates the use of U-shaped bent hangers. This ees 
gilat steel stirrup, woose sides extend downward, at their Tose 6 Pay 
er ends are holes for inserting a round pipe. Tne whole rests 
on the top pin &. ak The longitudinal beams directly Support 2 | 
toe centering and are held by the pin b. A wooden wedge between Mee eS 
the top flange and pin a serves to correctly locate the arran- : Pa OS 
»qgnent of tae centering. Tne two lower ends of tne flat bars | 

= also serve to support & Rangers scaifola for the work ot 
plastering. | nee 

Instead of the haggers may also be ased heavy wire as in a Fig. x ‘ : 
<8, passed around a flat bar, cut off at tae underside of tne e ae 
céiling after removal of the centering. , | 

Tne use of previously described flat bar hangers (Fig. 24) 
also follows for vaulted ceilings in a suitabie Way, aS visib-— 


eX 


seh 


SZ 

visible in Fig. ado The flat bars are oh se gah to the OH ye 
curve. | SR ae Ue ee | ee ee eee 
Fig. 30 represents an | arrangement of centering for vaulted — ae TOUS ake 
ceilings, such as introduced in the trade by Peschke Ca, inci oe on as 
bricken, These are all removable steel arch forms, consisting — i ete 
of two separable angles. On their lower flanges, they have ae By aes 
secure and not obstructing slide, but are entirely smooth on 
top. The hangers at right and lett are. easily adjustable to 
tne balcmness of ‘the floor and then wedged fast. Hor, reater _ 
Pp , Eoear ees dest 
pans these arcaes: are less suitable, since they are. : 
and dear. in all cases” is recommended the arrangement of a 
sabaaal 8 at the middle: hace tae “apline Pay ton-aseay aeene7e0e 


again for years. ‘ & 

A centering for vaulted ceilings by 
set on edge, which. Rest on the sre 
showa by Pigs Bay The cavities: pelted ax a 


of tae beams are tater filled. Beas 


as spident: ran ke 32, papmivtaag abstantiel sis; 
ot tbe beplacirye! Keek ane) saving of 1 eee 


sea yesh 


the slabs of ribbed floors a eet eee to 


hake a number ees lsaaaikc ak. ae same ane 1 in ne nie 
orn 
An ananrae at a anne 


se 7 ion 
gine Pee “$" 


AS soon ag” the anand jana) are.  fayasd, hels waar: 


naturally. removed. The. longitudinal -planks ¢ i ras, (eh 
the side wails serve “to bear the beams: for the slab centering. 


(Fig. 35 b). The sides themselves ate drawn don at the. ania 


Sandel: . 
Resist: 


lat eae “yy < ” Pe ae Die pot 
pe se i ee i Sy ee cans 


6 


- ‘ a “ws breast —< Pg Ons 
r Rr 4 “4 - , 7 lee. y ~ 
cs . ’ 3 » ork . ’ Eee DNs r 8. a ° Ki 
hs j i pt e+ a bo 7 / c >, 


ye . “83 oe oe elegy 
on account: of the arches, nha: the. ‘snort “‘potten Gis ot the” 
arch are nailed ‘on strips a (4 x 6 cn). ‘Saucn forms as are sors 
in Figs 34 are. best framed in the work} yard, thea» ‘pat. ‘together — 
at the place. of use. The gains for ‘the’ side beans (Fig. 35: De 
as a rule are only arranged when ‘the forms ef tne nain beams 
are built in place and aupporteds: 626 08 Pee eae Us 


Fig. 35 a shows the connection of slabs and bean forms as. a ae 
well as the required supports. The. number. of struta for eke 
beam is generally arranged according to the depth of tne beam; 
wide and deep beams (girders) require doubled struts; for the = 
smaller beams (longitudinal beams) suffige ‘gingly arranged oe Pe 


ruts. The struts stand at afStances of about 1.5 mw. (P. B80). 


Fig. 35 b exhibits the connection of a side beam form witha 
girder form. Tnese are first placed. On bota cross pieces aya, 
and at tae intessectbion with the girder form (Fig. 34) 1s nail- 


ed a snort plank {about 5 x 10 cn), which there pas to serve 
as support for the form of the sice béan. Tne connection wita. 
the form for a pier may then follow in a similar Way. | 

Of great practical use for we centering for flat as well as 
arched slab and T-beam fioors between masonry - walls may ‘be the 
“Universal Centering”of the General goncrete and Steel Co. Ber- 
lin. (Fig. 36). Tnis receives its entire fastening by pressure 
‘or insertion in the mortar joints. in a given case also suffi- 
ces simply placing on the last course of bricks. At the places 
of contact witn tae wali and with the frame timbers, the iron 
is ribbed for a better hold. Zhe height of tne centering is 
regulated by a corresponding choice of tne bearing ‘JQists and 
by inserted wedges. Ine universal framework requires no stifi- 
ening by struts. Toe excess in cost of the centering by more a 
cutting of tne wood is entirely ayolaed even for such combina- 
tions for larger spans, since the heignt of tne framework can 
be chosen to correspond to the existing lengths of timbers. © 
Tne advantage of tnis framework taus Consists in a substantial 


saving in lumber needed aud in wages. By Figs. 36 aud 37 is ev- 


ident the mode of use for small and sere spans. 
Forms tor supports. 2 
Forms for supports are always to be so arranged, that thee 


placing and tamping of the concrete mass may be done at an ‘Op- KS 


en side to be closed with tae progress of tne workl and Can. be ' 
accurately observed there. wor BUBETS cases suffices a foru = 


84 f 
for the sapport as in Fig. 35. Two boagd sides are nailed to oe 
4 vertical corner timbers (8 x Sjor § x 10 cm). The wall c MORE Le i 
sists of transverse pieces of boards, also nailed to tae corm- 
ii timbers.” Walls: d and c are closed, according bo the progress a 
of the. Work, =- Another | (advisable) ‘form is shown by Fig, 39. st eee era me 
At 3 sides” are. set vertical planks, (seen in plan as end wood), Pca ee 
which extend wo the girder and are connected together at. cert- ea Ros 
ain distances: ‘by nailed cross pieces, as. in Figs 34. The ‘box ; 
made taus may be constructed, on the: work yerd, and then ‘set up 
at se Hee of uses fo old ssagesnee of. e frames ney be used : 


the corner ) 


— a. i the angles of the | yates to ‘be hie | 
autered,. then: helmed ets arranged i os in Fass 39 


ea oe. At rotate: 90%, a0 thot the murteces ane\l vee ‘tog 


dear, PET Nigel eRe Oe aS aus | 

Kote. LepadBe aw pegara. Ao Me, ‘see the Thorban ayeten of 

Torus. BovVin,. Gontr\oas 4914, De he pe oe Anes 
in:all cases snould one. ‘take all possible care, thes. sh weme 


aos ae. > % Pw *y < ) 
, ah feet. : xf aha. ai! 
7 « - ' we - 


63 


MESON Pe a NPE. AE a) ks eae ie 
removing tne form no wavke® are to. be drama ak, and that. this” haan %, | 
removal may be done easily and nithout. shocks. - (Snserted. a 
bolts, clamps and tne like). — : aE 

If it be desired to secure the forms fron bending sidemise | 
of the filled. ends, a series of strips can be arranged as in 
Fig. 41, which can be removed on the second aay" atter, caning 
ana used elsewnere. Sey rs yen ee oe wa au 

P.9%3 4, Forms tor Partitions and | falas. Re ee Soe os 

The usual small thickness of . partitions requires the use. ‘of a 
forms wita side supports. Fig. 4Z2 a gives an example of tals. San ote 
wiooden struts, set according to the ‘progress of ‘the ‘conorete . 
wor between tac form walls -- provide Yor accurately preser-_ 
Ning tac thickness of the wall. In placing the concrete ae 
two or three boards are. placed above eaca ouner, in order RO 
tamp conveniently. . 5 

Nove LePe®S. Barturally one way of the Zorn noy be conplered 
%4O Vis entire ‘neVenr, then the atee\. skeleton ve set -- ond os 
for prvers -- whe second ward of +he fora ve fous as See work %, 
QAO GROSS. #3 ; oe 

for lene walls, tne forms may siac be wade portable ae aecoes 
ing to S$ketca 42 b. | | | ee te 
For particularly nigh walle & Support from the ground would 
be, too dear as a rule; then tne already Coupleted lower portion 
oi tne wall may be utilizea for fasteniug the forms for tae up | 
per part. as in Fig, 42 c. Tne form surfaces are neld wogetner 
oy bolts; for the surfaces may even be employed loops of . ‘anne= ee 
ie ateel wirs about 3 mm diameter as in Fig. 43. After reuo—* 

ng tne forums, tae wire can be cut off short. The remainder sot 
and the Lt of wood remains in the concrete, The fastening, of” sata: 
the form suffiaces in tae lower finisned portion of the concrete | 
is best by bolts. passing througa imbedded concrete tubes or ca 
hollow tiles, then drawn ‘Out and used again in other ‘Places. 
Toe noles are later filled with concrete. 

D. Means for making foncrete Wavertight. fe 

Tne concrete is not -pertectly Watertignt; it contains pores, 
that are connected together, and that must first be -elosed, 
oraer to make tae concrete more suitable. ‘En: practice. The ae 
crete 1s more Gemse, the greater the content oi cement, the | 
lorEee car ekahee. he mixing proportions are determined, tHe gr- < é 

and the strength obtained, and the older ® 8 ~~ 


‘t 
es 


86 8 
tne Concrete. Tae mass is to be mixed fully wet; a small excess of * 
waver is much less injurious taan too little. The structure of 
the concrete becomes ever denser in tine; concrete 18 not water- 
tigat at first, 12 1t pertianentiy comes in contact with water, 
1t may become gradually watertight. It must nave the fewest w 
crevices possible, but when the mixture is too ricn, is easily 
inclined to shrink, and is then dear on account of the high ce- 
ment content. Bxperlments have snown, that gravel as aggregate 
produces more #avorable results wnan crushed aPeees but that 
too much water reduces its dénsity. 7 

& particularly careful smoothing a the surfaces wet with wa- 
ter requires great labor cost, and seldom affords the desired 
result,. Particularly at the corners of water tanks will the 
desirea dénsity by smoothing only be produced in time. 

If special prepautions are taken to produce a perfect densi- 
ty, tae toliowing points are to be considered: -- 3 

a. The means must close the pores of the concrete wita cert- 
ainty and make them tight. 

db. The procedure must be readily checked and natcned. | 

ce. The means must atiord permanent protection from saa ds kind — 
of water. 

Gd. Loss of the means by naebeui ond abrasoon or by elsgtiewe 
changes of torm in tne whole, that have as a result breaks or 
cracks, must be prevented. | eke 

é. The means in a@ given case meet afford protection against 
.tne chemical effects of acid water or steal. : oe 

{. fhe méans must be free trom injurious materials, ahd aft- Dee ge ae 
ect tne strengtn 6f the concrete as little as possible, er a 

Tne use of special cements, for example of Star cement, with PR ge ye 
water resisting properties (addition of resinous: substances), 
as well as the use of additions in making the concrete are ‘gen So ge 
erally less common that the use of plastering and coatings. gi? i 
For reinforced concrete onid plastering and coatings come into. . 8 
Consideration -- or kes mip water bressure: _— - special: Sign ep Aa a 
facings. | | wea eae to) SP ge 

i. Use of added Materials ia dikes bes tne Concrete. oe ee ee 

Various means, representing potash soaps or tar mixtures, tees copia b, £ > 
are added to the mixing water, thus giving to the concrete Was Sada 2 
vertight properties, fhe same end is. attained by hydraulic. ce- a F 
tenting substances: de coigetnces ineds: Materials of acid | mavure na= 


ce 


os ‘ ey : salaats 
nabure have & , decomposing effect. Concrete with a properly se- didgale ane) 
lected addition also. then Pemains still watertight, eet: Bie : 


ues of, the outer surface result from mechanteal abrasion (of 

running water - containing ‘sand, tor example). In. the- phepatagion | 
of the Concrete is completed. the work of making iv bight. Pm 
advantages; -~- ‘generally eduction of ‘strengtn 2 5 aa the: ‘concrete, | Sa ga RRO Eas Cae 
‘ince the additions may wore or less’ hinder the necessary firm cae) Bets 
cementing togetaer of ‘the different materials; retarded sevtings © 
no protection from chemical ‘injuries (only ‘intended for chem- 
cally bad water); bad control in use (not always: & proper dis- 
tribution of the added materials); ‘mostly unsuitable for ‘rein-— 
forced concrete. The- main thing in every case is. a ‘thorougaly nee 
approximate making: ot the concrete; defects in vhat cannot be Bs 
compensated by tne addition of materials to make it tight. eee 

As preferable additions: have proved to. be hydraubic. limes ad 
(or also Roman cements). If one substitutes in concrete tor ee 
part portland cement this material, then its. tightaeas is. ‘ine- 
reased ib an important measures For a rich mixture ‘is - to be ta: 
ken less, for lean ones more addition of lime. Tne mixtare A 
i cement + 1/@ lime + 3 sand already proves to be watertignt | aed ye RCeROLD cert gcs 
after 6 days. The more sand, the more lime paste is to be take * oe eee. 
en; thus tne richer the mixture, tne less the addition (addit~ ae 
ion about in proportion of i/e@ to 2 parts” by, weightzto i pare 66 Ae . 
by weight of cement). The strength is little changed therebp, 
less in any case than’ by the use of fat lime, which is there= Ry ae et aa 
tore never to be. recommended. But. St: ‘the strength be. not sO. ek See 
very important, then can concrete be ade practically entirely — ee eae 
watertignt by tne sCoadet ale of fat lime tor alt vane Fortl= 
and cement. . ee ’ BS aee, 

Ravorable is an addition of trass ‘mad rhe” 4, Trass nlove =: oe ae 
causes delay in nardeuing; put lise water favors the nardening le aie 
of the mixture prepared with trass. Tne base of trass is the | i . 
tuta stone formed of ejected volcanic trachnyte masses, that @ 
occur in pangs chiefly iD the provinbe of of Vorder titel sete). 
te valley). | isi Saas : 

Kote Lopes See Gourtrvos. of Royal Testing Lavoratory, eee : 
Vin-Gross-Lichterfelde. & 1813. Heft 2, GS weld as evra. {ar 
Trvefbau, 1914. pe 132. 

Note 2epeWGe. The particular peculiarities of trass-tufo are 


& Gefinvte content of Vadluded aViicbcactd ana hydrated water, 


. IS: ‘pects : 
G8 WELW as Vag vovune with the way o. frnety qreth: (ton tease”), ote See te 
-- tras. coment wortar attains greater ‘strength, WAR wavenanetng ares Mons 
age than trees Vane mortar, | | Ie CO 
A cheap » method, ‘but to ‘be employed With care, is the addi nk . 
Fe, grease soap: (potash soap made with good. rapeseed OF sess 
bub no ordinary washing S0ap, and no alkaline grease soap! a Pe Regs oo 
The soap must be ‘completely dissolved for use, best in warm © es pas 
water. One takes for 100. litres: ot water: 4 to 8 kilos of soap; 
cement about. 490. ‘kil /n3 for concrete, sizes of. aggregate. up to. , ast pis 
165 cm. Also advantageous is. a smooth plastering about $5. ee 
thick composed of 3 fine sand, si cement, and water with the same 
content of SOaPe One m>- of. concrete is: about ce ‘to. 


10 marks: dea- 
rer than’ without this addition. The greater ‘the addition ‘of i 


S08D, the | more: HAUSE SEED Sat ‘but so. ries ume more 18° » the Peduet 


the setting period is. ‘shortened, “80° that. its. use. in | summer ap. 
pears questionable.  Gakeeeane the / Presence of 1 the mei 


NOtSY LePe BT eeke" neutral potash: soaee free. from aeka wan a’ 
considered. AVkabies destray. he | eoncretes == Moreover. to we 
recommended Vs on adavtvon ot sross” ot whe sane. time, since & 


for Karéeninge se es Cut S. (eg SNe a aan aes 
Note 2. pe. ‘Thus epectal cone oe: necessary, Andocd woth for 
the winerav ove aS Well as for Lhe ON from vetroleun restdnes. — Wirth: Co Crna CS 
Instead of tne soap may be taken an addition of oil, about — Te oan 
5 to 10 pec. of the cement contained. Benefits and ‘disadvante~ Ca a 
ges are about, the same. 2 According to Page, plastering ib to. We ss 
20 mm thick makes it entirely watertight. een en 
NOLS Boe BTe See. Gente. &. Bawoe 1912, Kos. Shy thy 45, 28.7 
Note hepo97- Bee B&B, 1841. p. 18, 1848, AGAR. ve 808. et east 
AV. Bo AQ12e De 4h, Bhde eee oes 
Biber (Oornel Esser, ‘KOln-Bhrenfeld) issbentietiy, ‘consists Py sabes 
bituminous waterials; it is added to the completed mortar. itt mae 
1S not combustible, and has proved itself in very many cases are 
an excellent material for making concrete waterbignt.? ; yee 
Kote 5.p.87- Me watertabs for woking watertignt and for co- ae 
otings mentioned in this and. Ae Wext Sectrvon have proved them= 


Ye 


Selecs as actually usable An practice. The composytion of the 
Naterlals Ve naturally a secret of the manufactory, by aLreot: 


89 
Vnguiry of te Go. way be obtained ocourate infornotlon conaern= 
yng COSt and usee There VS a numer of other outhentic weans, 
dut which are similar ta noture to those mentioned here. 
Aquabar (“Aquabar G.m.b.H, Berlin), a paste composed of org- 
anic and inorganic substances, is packed in boxes. It is diss- 
olved in water, and the Concrete or cement mortar is made with 
this solution in tne usual way. Tne cost of i n? of concrete 
1:3:5 is increased by this addition only 1 tn 1.5 marks. The 
property of agqguabar to intimately unite with tae components of 
tae water 1s based on the great content of included silicic = 
acid, that crystallizes and forms fixed combinations. It-torms 
an entirely safe protection from dampness and ground water, = | 
Tne strength of the concrete is reduced bgt little by the add— 
1tion of agquabar, at wost up to 5 p.c. Lg 
oe Po peolite addition for mortar (A. Pree, Dresden) is , added to 
the water for miking or to the mixture of cement and sand. Th- 
ere is needed for 1 a concrete or mortar 20 to 25 kil additi- te 
on (supplied in form of paste or powder). fhe Preolite. addition 
for mortar dees not color tne plastering, also has no injurious 
effect on tne tensile and compressile  Strengtn of Ane. mesure. ee 
and also does not delay the setting. + i . nee Pe, ee J 
Kote 1.69.98. A siwilor addition is Ceresite, Pate area ae 
2. Plastering for Waterfroofing. eis 
Plastering can be applied immediately after the. opapaesiGn: 
of the structure (painting only after complete drying). But a ae 
one waits for any settlement of the structure; plastering ais” yee 
never done in freezing weather, and in summer must be protects = 
ed from suns#ine. ‘The greater the content of cement, so much ea oe : 
the more effective is the plastering against. vibrations; te 
necessary the plastering may ‘be secured. by fine wire netting. 
In plastering tne corners of rectangular tanks, especial eare. Pe ene 
naturally is to be takena Disadvantageous . for. all plambering 
is the posskbility of the formation of hair cracks, which by . cue, 
tae effect of acid water may result in the destraction of. the” 5 8S eye ere 
entire layer of plaster. AS a protection against mechanical. Mee ha Pe 
Juries is employed for floors special coatings of Goncerete Top é 
Stone paving, for walls. covering with glazet tiles ‘or the like. 
Covering witn cement ‘plastering (smoont coating) without any eee fe: MG 
addition, after a previous cleaning and moistening of the: wall. eS el 
Mixture 1:1 to i; 2 faa. a m9 ‘sand about ict head 600 ail sonent)e Dt Rn 


90 
{Toaickness of the layer at least 2 cm. The surface to be smoota- 
ed plain with the rubbing board or steel trowel (rubbed). Neat 
cement can only be employed for the entire layer, when the pl- 
astering is permanently under water or reuains in closed rooms, 
taus not being exposed to sunshineor air currents. The plaster- 
ing must first be completely hardened, before it comes into use, 

Note. 2.8. The postering mortar wust ve made as fresh as 
possiobe. Likewise the surface in question must ve plastered . 
wWirthourt wnbervuptions as nearly as possible. 

dse of a cement plastering with additions at tae same time 
for protection from chemical injuries. ‘ 

Biberol (Gornel Esser, C8la-#narenfeld) is a paste addition 
witnout color or odor for plastering, which does not crack, = 
prevents flakiug, and each coat after drying in air, receives. 
oil colors and varnishes. Biberol is added to the water for & 
the mortar. There is required for i at? external” plastering 1S 
cm thick about 1/6 kil, and for 1 re ‘cellar plastering 2.5 cm 
taick shone 1/4 kil. Cost at Cologne 6.80 to 0.90 mark per kil. 

Auameneon! (A.W. Andarnacn, Beuel-o-Ra. ) is a gelatinous mass 
without color or odor. In consequence of ats: antiseptic effect 
dwa also protects against formation of nould ang Tunguse Is: 
possesses a very strong resistance to water. According to cer- nee 
tificate of the Royal Materiais Testing Laboratory in Gross-L 
licnterfelde, Awa ‘peaists 3 perfectly a water ‘pressure of 6. G4 Sig hoe oes eae 
abMOSPREreSe ey ees DN NG ow ay oe | ne ee 

Lime and trass addi ston, re cement. +41 lime + 2 to 3 stad = eA Bal att 
not too coarse and of. mixed sizes of grains. A mixture 1; 1: 4 pe 
has a reduced hb son can as well as ‘too oft cae sevting and narden- 
ing periods. Fr hgh Sacto RP ite ate: 

Yor small tanks of subordinate. importance sufficies a coating 
of the internal surfaces of tne walls. wit clay or. milk sen 
nent. + Also see B& ‘Be. 1912. Pe 393. Le ANH oR patty Saha a 

Nove LePsBQe ‘vhe- cenent powder: Ne scattered over. ANE caster. 
WTR GOnstanrt Stirring. “Tae. coating. material: vs to be roplaly 
Used wT further. continued atipring, since otherutse the com chetleetaiaer tS 
ent Sets and nerdens On. ane wut{ace. Phe surfaces | x0 be. wrested Cid 
are previous by. %O be. Shoroughly wetted. . neo : a2 

3. Coatings for Waterproofing. Mi Aor ee am beat prscks ets 

There are employed preparations of tar and of soap, phat. fill 

the pores of . ‘the surtace : with a matorproofing. sediment. They 


ch peogt 4: 


to EE 
ae e 


at we yprs ae Fee 
; 4 were y i a \ 7 


94 ye eae ne ee aye roe a “s 
present the following advantagest~ possibility. of checking tae fae 
work afterwards by the appearance, | avoidance of hair. racks, — Be oA 
protection from the effect of water and from. chemical pre eo 
as well as from water in mortar containing. pda is: Fsbo ge ES anes 


tne application of the coshiag,) $0. “that. ‘one mast wait asta ~ 
tne concrete has entirely nardened ‘and. ‘dried. ‘Naturally ‘bhe- x 
coatingmust not be injured. ab. any ‘place, ‘since otherwise the See un on en 
‘noisture would gain admission ‘to the. unprotected. concrete. Cor- Ee 
ners are always to be avoided. or rounded. ‘for ‘the usual. aspnaly Nae sae 
coating is | required. at least to “applications; the s ‘second coat 


(whicao often takes several, pie ee sie 
Kote Be PeW@e One : As. eotuathy » never Pkt ses sate from. bied 
effect of acta. worer. Rtas ae 5 oth te re ae a 
One of the best patabiagwayeriaiy is ‘sae. nervolgt P Past ben 
caler Co,. stuttgart. It is a. paint ready for use, approwed tar: 
several years, which. serves: to waterproof cement plastering Ce 
and to preserve ‘concrete structures, endangered. by waver, damp-— a Say aaa 
ness, dilute acids and. the Tike. Inertol not only forms: a ity ene 
face skin but penetrates: into. the cement and concrete, sO that . 
a coating of inertel can scarcely ke rubbed. off. Fully dried. Sa eee ae 
inertol nas no odor, and gives: no: ‘taste to drinking water. ee 
Inertol nas saa a muco higher. flame point than ‘turpentine wR aes 
tor example, and paints containing benzole or turpentine oil. ee 
Inertol is prepared cold and dries very rapidly. ‘fhe spread of ee oe 
it is considerable; tor twice coating 100 mn? of cement surface se ca ee 
is reckoned about 30 kil inertol. (A cask: containlag 200 kil * eh aaa 
costs at Worms 76 marks per 100° kil). According to. ‘thorough. ee he 
experiments at the Waterials Testing haboratory of the Royal = 
Polytecanic Sckool in Stuttgart, the formation et PPHOE hac ae | 
Cracks 1n cement and concrete can be iessened; . existing ‘shrink- ee 
age svacks can be permanently covered and made tee by coati- Ae 
ngs of inertol. : Sone oes EP SER RO BAER 
Note 1.+p.100. inertov. hoe been very commonly euployed AN . 
tonks for drinking water ond evsewnere, ADY. et fecr of. yoete: Or. 
odor of the water by aried Anertod has wot yer een observed, 
Purther see Gant -4. Bau. 4206, HO» TS, 1912, RO. 38, also Be- 
UVS. Bouze, 1908, Ro. 24,8 & Be 4942. pe 301, 
Slack Siderostnen-Lubrose (Johannes Jeserich Ca, Charlotten- 


¢ 


« 


G2 
berg-Berlin) is a protective coating of especially great spread, 
and iS applied cold. itn i kil may be covered at the first = 
coating 4 to 10 n*, according to the nature of the surface to 
be covered; correspondingly more with the second coat. This @ 
covers the mass witb an elastic coatings like rubber, which is 
extremely resistant to akmospneric influences, as well as to 
the injurious effects of ac&ad and alkaline waters, to free car~ 
conic acid in water, rotten moss, etc. The skin coating produ- 
ced by 1t 18 not aifected by wired daaben changes in GOBSERBERGE 
a its high elasticity. 
pis Preolite (4.Pree, Dresden) is a black paint free from tar, 
of a thick fluid varnish nature. it is delivered ready for use, 
unites tirmly with the concrete and is entirely resistant to 
acids and alkagies. At a test in the Royal wechanical-Tecnnical 
ixperimental Laboratory in Dresden under water pressure of 12 
atmospheres {water column of 120 m), there appeared neither ad- 
wission of water or moisture into the test body. 
NOtS Le PeiOL. See opinion of Prof. Dr. Bohand, Stuttgart. 
Contrios. 1908. pe. 64, abso EB & B,. 19144, Ae Baie : 
Nigrite (Rosenzweig & Baumann, Cassel),+ applied twice, ‘soaks 
into the pores of the concrete and forms a very usable paint 
against dilute acids, ammonia water, carbonic acid water, etc. 
Also under the influence of fumes of muriatic acid, nigrbte 
Shows no alterations; it even exhibits a great resistance to. = 
tae well known strongly effective acetic acid. Plaking of nige 
rite trom cement does not occur. | 2 
Finally, attention should be called to a. procedure especially 
favored 1n America, tae so-called Sylvester ‘process. nis con- 
Sists in preparing a 5 psc. solution of alum and & 7 Dele eee 
tion of soap; the soap solution is then “applied with a soft ci S76 
whitewash brush to the clean surfaces. ‘After the coat ‘has. dri-- 
ed somewhat it 18 brushed with clean water to remove trom tae 
surface the superfluous soap. solution, and then follows ‘the : a ly 
Final coating with tae alum solution. STEN? ii OS ar ie aa 
On Oil painting, ‘see. Pe 113. On. Ea aes paints (Droese e = 
Fischer, Berlin-Friedenau), see Part Bae ae a th. edit. De ad 


4, Use of Covering Waterials in Form of Slabs, as 
They serve for protection against fine. penetration of ground eeragte 


water and as waterproof ‘coverings: of bridges, passages, ‘ein. e 
etc. In every case ne mast be sufficiently as atonts ie DAES 


~~ 


Le ee 
BLS © - 


participate an sligat movements of the. structure s without danger. ; 
In consideration come tarefelt, asphalt layers, saturated fab-— : 
rics (felt, ‘jute, cloth, pasteboard or the Tike). with flexible | 
protecting. ‘coats of asphalt. On both - sides, sheet lead with Pei ie 
le Caalt Coatings, } In regard ‘to the arrangement of such protect. — 
ing layers for asp ueapercann Sarat ‘eee: Part I, ti th edit. 
Pe 158. 2 = ah ns seh es 
Note | Le p4i02, bead, alone ve suvseot, te destrection Me, Vine 


or oghent. oa 
Note Be PeiO2. Aveo | see. , Seuline, Noterprooting stornet, ey Ree ho a 
und Kater. 1943. Ru. Ernst. & Son. Borin. ae tea: MES eke ey eee ee 
&. Precautions against Ghemical aod Hestroly tical Btfects. ee ete 
Danger from bightning. a ee. o 
Unprotected concrete. sfgedou0h feet, sence. 8, protection com ee 
es into consideration | Att ss materials mention~ 


ed on p. 95 and 99, besides. tacings of ‘glazed clay tiles, Glee, 
porcelain and slate slabs, slabs. proof against acids (Gnamotte : 
stone) and pottery slabs: (Kgnautit’s slabs). ‘The joints: Men R arin 
as fine as possible and be filled with good acid proof Look h Ee ec meee 


(For example with a mixture of red lead and glycerine combined ht um ee 
as a cement). ‘The main point is a suoothly executed covering © OS ot SES ea 
of the cement surfaces. = PUG ete oe Fe ay 

Acid fumes are not injurious; yet also here is “souetines: to Be ae Bi cs 
be recommended a protecting coatings = = we ee ge 


Following are described various materials in regard to ‘their. ae 

chemical effect on concrete and the reverse. ete et ee ae es 
i. Acids. Cee elias a es cae pe he 

Very injurious are the strong seins. particularly ena ag ew! Ge 
combine with the lime of the cement in soluble lime salts; mu- a 
riatic acid, acetic acid. | : Pusey oye cas) one Es 2 

Injurious are further sucha acids that give with ‘Lime insol- Pa GR Oe ar a 
uble or but diffieultly soluble combinations; taere is here + eee ee Se 
formed a protecting coating; sulphuric acid, ‘fluoric acia, ‘sul- coh aCe ee 
pnurous acid. 2 Ges ashy NS AG ok ie Pa eee? 

Kove 3. PelO2, See Bk Be 19th. pe dg eRe See Ar 

injurious is also tannic acid; very injurious is- ‘lactic acid. ee 
(For example, 1t 1s formed in fermenting sauerkraut; ‘cement a me: : 
wash “in dairies). - : : 

Very injurious is - tree akacs acid ‘aissolved In water. 


AS a permissible means oe protection S&gainst very ailute ace, 


re 


oa 


| 94 . 
acids Caveat dp vO0) is to be regarded Nigrite. t Results with | 
mariatic acid, acetic acids, etce). Otherwise a covering with 
tiles’ Giettlacn. tiles, glass plates, etc.); also lining wita . 
sheet lead (dear). Seabing with tar affords no permanent Pron. 
tection. ee ine pie pes 3 

“Xote: Ae PolOS. See Re AOL. Another moons V3 concrete. duro Vine 
OURS SUS. Bort, Ty 2.3 <n edition, Po We <3 Dio agro SPO eho Oy. 

aes Bermenting Fluids. at | fe pene egg are 

They have an ‘injurious. eifent. by. tne formation of carbonic_ ae gers 
acid; saturation of ‘the: surface by tartaric acid or perenne 
icon carbonate . wicks Breer a anit 2 oe Bs Ya: 

Very injurious is. fermenting beer. (also. béesuse acid) with: 
tannic and carbonic acids. “ fhe means for protection here must : 
not disturb the process: of fermentation and neither yield. taste 
nor smell. (Goatings: wath fluids containing silicic. acid ora 
solution of: ‘cream of tartar; Weralite of. Rosenzweig a Baumann 3 
CO, Cassel; a Waxy coating of. ‘paraffine | 2. after complete apn | 


dening of the concrete; | ‘Lining. with acid. proof. plates or clay Te Beas 


tiles; cowering with sheet alaminion 18. very advantageous). — ne 
Kote de> Bnder fermented beer wit Ness whan Oot meee. Disiakr iy ot 
cantent WOY already, ke -Anjurious. ie - en ie Cee ees 

Korte SePslOFe Burt Restn-Rarot {ine coatings, neve. Vso Areques ere a pate 
aty nod .on Vajurivous effect ‘On. the deposit, ond veomaiming of ee tae 
youst. Vn rotaforced.. sonovete. Somks, See B oe Be ABA beet te 

‘35 Fare, Oils. Ry ae a OED Ns een e. TE a 

injurious here is the possibility. of. forming acids; ‘the nore — 
sebacic acid contained, the greater. bhe injurious: effect. ae 

far exnibits no unfavorable. infleence. _ ie 


Mineral oils: are but Sligntly injurious, but under some con- Ce 


ditions. produce. a slight reduction of strength, ameiaanes ae ae 
crude oil, cpaptha, ‘vulean oil). Good phantering with cement Se he 
coating is mostly. sufficient . we Re ORS A 

Note - ‘he og 108. See BR * ‘Bs AMLhe Pe 2596 ) * 
pig Gciieaa. are also ‘the fatty oils, indeed on account es he 
formation of free sebacie acid by transformation. Animal oils; 
tallow, train oil, ‘neatsfoot oil; vegetable oils; rapeseed, * we 
olive, castor, sesene oils. As, protection; dense concrete, - | 
good plastering, Painting : ‘sbuaten?. covering wita tiles; but 
no asphalt. ie eas rear 

Note “Le Deidd. Gancvete Awnererioes: .0f Seyi hte bed are groauathy 


95 
evaduckby Gestroyed vy contanually SE SEPA R vapesecd ov and 
LGALVOWs 
4. Sewage, City Sewage, Manufactory Sewage. By 

Sewage in itself does not affect concrete. Carbonic acid in 
sewer water and also in sewer air (2 to 5 pec.) does not attack 
the concrete. ‘bikewise dilute acids (up to 0.1 pec.) are ‘Rot 
injurious. S553 vet aie 

Kote 3.pel04. Patty and slimy. matters found in some waters 
Beposss an the walls the so- calbed | Sewer coatingd, whieh offores 
% 2004 protection. In any CUBS, -experrvence has. toudht, shat a 
concrete Vs well preserved of ter Vong years for sewer works ot 
OLY kinds. ‘Bor water containing | carbonic OCG a quite dense. 
wixture Vs tO be taken for the concrete, . ae 

Injurious are concentrated acids (for example at paeces of 
tae entrance of more acid water from manufactories). Tne effect 
is still more injurious wits mechanical friction of the sedin- 
ent. (bines with strong fall and. sliding sand). Protecting me~— 
ans; Coating with asphalt. varnign applied DOL, EbCe; lining 2 se 
With glazed tiles, construction, with hard burned clinkers, can 
st acid proof asphalt irc whicl wi dD end Joints: baal ‘sephalt (for 


PEDOR AG Fc ee Fog aE a el eet ee SNS 
Requiring nO thougat ‘is. ‘tae ‘si wade. ‘from dyenorks, tanneries, | aa ae 
bleacheries, paper, sugar, oil and fat manufactories, cloth Bee a es 


and cotton factories, starch factories. (All. wastes with alka- 
line and neutral reactions). Pinally unecessary is the consid- | 
eration, also of breweries and distilleries, ae rkiS) ae 
On the other hand aré injuries of wastes” from sulphuric and | 
puriatic acids factories, from factories of artificial eae 
izers, ‘from binning works, brass foundries, from ammonia and — 
chloride of. lime manufactories, coal mines, etc. eee 
5+ Mineral and Thermal Waters, “Alkalies, ‘Salt. a ANS 


The aptene are Rot Anieesonas ye oul are saturated wit ‘83 


than 50° C. For mineral waters: the molsoular coatalaed. 8 eathonic ate ee 
acid way be dangerous. ~— Cement pipes for pipes from thermal ee ee 
springs require a protective meavengs ‘Springs containing come ie Ga ey 
On salt are not injurious, ) | 7 Be a 
Bore alkalies are without injurious. aaduences) (potasn, anda ie ide 
ammonia) .-- Injurious’ in spring water with magnesium sulphate ao hy cee ‘ 
(bitter water).-- Carbonates ot alkalies | are not Etc dh unmade! CRANES oS Meee 


-— 


aK 


vanes Be eae oe 96 fe 
“even increasing the strengtn ‘of the: ‘saunas cued; (sodiun care 
donate)» potassium carbonate, aumonimm carbonate. 


Neither ‘injupious. are the haloid salts of the alkalies; pot- 


adsivn enloride, common ‘salt. (sodiug chloride), ad salammoniac Caen 


-(enmonium ‘enloride). mes Calcium enloride and ‘salpetre (potass- ae 
ium er sodium Bitertas . are likewise pot ‘injurious. Wagnesiun 

chloride ‘anjuriously affects the hardening. -~ Injarious effe- 
cts. have the salphate salts soluble in water (potassium, sodi+. 
ay calcium, eron and magnesiun sulphates” (bitter water). : 
3 “Moke Aspel0S. According. LO experiments of Termajer even Stee 


ong solutions: at common Babe but. BKAGKLV Teauce the conpress~ i ae pee: 


NS ; avrength Wn Gouparisen ARR whe see: generalvy weed. ne 
Bae Hot Water, Steam i | oe 

“Hes: water above 50° Chas an injurious ‘effect, ‘and ‘ait 2 
also not steam. ‘That is parbicularly true for tanks in cold & | 
external air (great difference of temperature between external 
and ‘internal surfaces). Previous cooling of the water in pipes; 
or. double walls and heating she agverapace before filling the” 
hot water tank. ae Mig oe 

Kore Bepei0d, % Se Auerico orkiehoiat vlocks of cement are ot 
RON sreated witH stean Mader pressure va order to. season. then 
BAP VLOEN, ond vo place. then on SOLSs Experiments hove. shown, e 
that steam pressure wp ‘to 54S kiv\on™ -geeeveretes the wardening 
na Anorecsed. the etrength, APW. Be. 1213. Pe 347. 

‘7. Pare Water, Water containing Garbonic Acid. © ua 
Generally pure water ‘is not injurious, assuming good plast- es 
ering. But already water wita little mineral componénts in so~ 
lution may be injurious, | whea flowing permanently through con- 
crete tanks. {Water reservoirs, settling basins). 

Most injurious is> ‘carbonic acid in solution in water; prote~ ; 
evion; plastering 1: 1, faced with neat cement, and BETREANE 
With tnertol, siderosthen, or the dike. 

8. Ground and Bog Waters 
Ground water is injurious if it contains nitrate salts or ¢ 
Caemicals, for example those serving to parify water for boil- 
ers or for other purposes. 

Humic acid delays the hardening of the CONCre te. 

bos water is injurious, since besides humic acid it frequent- 
ly contains also iron a and free sulphuric acid (ground 
Containing pyrites). + ‘fmportant for foundations and sewers; 


97 

@ previous Chemical examination of the ground and water is ab= 
solutely aecessary before the construction. 

Note 1.92106. In Osnoburgd a tomped concrete sewer was entire- 
Ly sestroyea by vod earth See ASE PY VISES. 

Se Sea Water. 

Sea Water may have an ‘injurious effect, indeed laaiefis from 
the nagnesium Chloride and sulphate contained in it, These sal- — 
ts may Cause a reduced sbrengtn of the concrete hardened An 
sea Water. s 

Unfavorable is the uniform ee of the waves as well as. the: 
alternation of ebb and flow; the concrete is alternately web . 
and dry. (Constant change in volume). eo See OE Fe 

But recent experiments and observations have sown, that the . 
rect of sea water is scarcely of ‘importance, if it- concerns» bs 
good ana well tamped. conerete with & rich mixture for: the ext 


. 


ernal surface.  —- ta eo oe er 
Addition of trass has but a limited value. On the ‘cubes. baa: Co See 
see Essay of Dr. Hambloca in Ara. Pa casre De 83. Bares eae i ee 
10.Suoke Gases. : be de auc 


The injury from suwoke gases } 4 tor conerete masses (railway — 
bridges, chimneys, locomotive sheds, heating | pipes, etc.) AW ue aaa, 
without importance; experiments have Shown with experience, Oe es werk 
that the gases penetrate little into the concrete. Gore a 

Note 1epsiO%, Suoke gases onvet hy consist. of. a strongly heot- 
2d Wixture of aly with steon, ‘sulphurous oCte ond ented force * es eo 

Carbonic acid gas is not injurious, but even aaa’ the Mirdenn 8 
ing of the concrete. Only gases containing sulphur can affect BS Ses 
concrete injurioasly. 9 ¢ fie oe oe ae eileen 

ii. Metals. a re ee 

Lead is destroyed by cement, especially 1 in porous: concrete. Be ee 
lead pipes aré painted with asphalt varnish. i < ea SNe 

Zinc way also be attacked by cement, 4s ‘protection is mecenn ih 


mended painting wita asphalt or a thin coating of lime paste. | re 
filectrolytice Influences. (Danger tom Sls <0 C ege 


Concrete ia a ary condition is a. bad conductor of. electric 
currents from machines, Lighting and weak currents. On the con-* 
trary, if it be surrounded by earth, whose moisture ‘is transf- | 
erred to the conerete, then it will act as an electrical cond~ Ran : 
actor. Qnly in such thorougaly damp reinforced concrete can a na ar ees a 


et ea Bs th 47" Wor anes - . 
se ‘ Pe ea ee 


occur injurious effects of electric currents: (nosning | ‘$e to 


: Shs a7 RN eS ee Soe 
> Yo a w4 me Oe ant 
; 


aie 


A.10 


a 
| 98 


be feared ik old ana dry -eoncrete); if the damp- reinforced gous 


crete is permanently traversed by Constant ourrent electricity, 2 
then first occurs an electrolytic decomposition | of the water i 


‘and a rusting of the reinforcement. famped | concrete without © 


reinforcement is not injured by. saghiot ahatated ‘in dry"or wet con~ 
dition. | ; 

Note VePelOT. With alternatyng Sernanva, On. eveotrowytte ote 
Leet CAMNOt OCCU. Ret ji 

Note LepPeiOB. A veny small odaLtvon of & 8av% (soda, counon 
soe) Lnoreases the appearance of destruction an quite Awport= 
ANE WSASUMSs e 

The rails of an electric railway bedded in reinforled coacr- 

atl 
ete are eet te exposed to wandering (return) currents, as m. 
well as to such currents that leave the proper conductors, and 
produce electrolytic effects in the neignborins pipes (water 
and gas mains) in combination wita tac dampness of the ground. 
inese weak currents, but which tlow for a long time regularly : 
through the reinforced concrete, nave effects far more inguri-— 
ous than currents of higner tension and voltage, that only oc- 
cur tor a brief time. The wandering currents are only witnout 
daanger as long as the concrete is ary. 

The best means for protection against the aanger of aleterel. 
ysis (formation of rust ana bursting of the concrete) is a good 
insulation of the reinforced concrete from dampness by protec- 
tion with aspnalt, tar coatings, or tne like, a good insulati- 
on of all electrical conductors, particularly of isolated bea- 
ms embedded in concrete, and good insulation of all.pipins at 
the entrance and 6xit. Besides care must be taken to have a @ 
sufficient covering of the reinforcement; witn careful execut- 
ion a layer 2 cm tnick suffices, - 

Gehler, Dresden, established the avinwi ne by gee tS 

Note] 2ep.i08. B & Be 1910. Bett 44, 12. 

1. For tamped concrete-witnout reinforcement no notable red- 
uction of the compressile resistance is to be Sept bi from 
the effect of the electric current. | / 

Z. For large steel snapes embedded ‘in conerete occurs | pare 
1f the steel forms the positive electrode, so” that bursting of 
the enclosing concrete liass may Occur. . 

3. For ordinary reinforced conerete structures according bo 
results so far knowa, no anxiety occurs concerning the effect 


vi 


a) 


99 
of tne electric current. - 
Brandt, Darmstadt, made thorough experiments with reintor- 
ced concrete cubes of 30 cm sides, that were exposed to the = 
various effects of the electric current. For a number of cubes 
the reinforcement was exposed for about 6 hours daily for two 
years to a current of 140 volts and at least 6 amperes; neita-~ 
er @id it show the formation of gust nor was the concret soft- 
enede Further experiments led to the judgment, that at all su- 
ch places where the concrete is in damp or wet condition and : 
is not sufficiently insulated, formation of rust occurs on the 
reinforcement -- and ‘in consequence of expansion by rust -- Ss 
bursting appears in time, as soon as this concrete is exposed — 
to an electrolytic current (constant current). < Te assumpti~ 
on appears entirely justified, that for weil dried reinforced 
concrete structures in drgy air no danger of any Kind exists . wove: 
for destruction by electrolytic influences. 3 Care was here &° i 
taken, that the current used in the. experiments was 70 wines 26 
as strong as ‘those wandering earth currents could be. : 
Further see B & B. 1912. p. 223; 1913, p. 132, 290, 306, 331, 
445. -- Cent d. Bauv. ees °oe 75; 1913. No. 50. -- Arm. B, 
1911. 16.350; 1944, -D,. 32; 12 Be 32; 1913, -p. 166. pia gay 
Note 4. pei0B, teft 6 of she Belava0 see B & Be 4012, Supple 
SWAN HOt te . 
NOUS? ®2ePelOB, Naturally for ourirlartngs. une ye\atonannents oe 
st not by® fasteninds be placed in airect cannection with whe is 
electric conductors: of strong currents, 
Note 340-2109. The vest protection As. forned by -' coating Of 
resine Mixtures of soap, Covesrvrte OF. the Vike. Ges 268) for waki~ ay 


WE CONncTStSe Water tLEnrt ore » aia NESS AEN ES wRaer: eLectrolytic Se ae oS Se 


Wf Wuences. IP hs oak Sree te ORES 1S iE eee tania 
bigntning strokes produce only. local a habuancon: in. a tein Ae 
torced concrete structure, where they must pass through badly 2 


conducting masses. (@oncrete without reinforcement). But wouade ha Beas 
ly the stroke is carried off by the. steel ‘skeleton embedded “in ie Sree 


the concrete in a- sufficiently permissible manner; slight: ‘inju- Se 
ries to the conerete covering at the places struck, and at. gla 
p97 where the Lightning must ppring from one iroa rod to anot- 
Bese. Within the concrete masses means little. + hk special - ‘prot— 
ection from lightning (copper rods) is not netessary; but it ~ 
is advisable to connect the steel reinforcements by wires eve- 


PE ESE 4 


4 iy ae : ¥ , “ : a Shin 2s : pul, 
eu. 8 i 8 ras : <u Rese ae She o> 
rae Pipes ah x , Rae ‘. ma Be nieee ne 
hy cg } iy oat ere Neat =f here . ¥ 5 Te ed eRe poy * 
ier’ OP Re COMI E LS nak ee r A oy ANB ‘ i 
ee . at ¥ i> a) . > 
eae Poste ios “y $e 
‘ £ . 


west gutters and the ‘\eadanke: ay: ais Likewise Feconsended ee 
join tae reinforcements below o 
catch the aimoks: tasers to | 


extead wore ee abade! olen’ above ‘get part of ‘the. ‘Bublesndos’ 
(ridge of vreot). 3 We ‘danger’ to life exists: from a ‘Mightning 
stroke, since tae: con ductor as. enclosed. entirely in banter 
Kote LoVe AO | Thane e-une forned, ‘the ao-calies, Sot wie | 


Note 3, Pell. ‘one. aay. ‘alec use, orasnental. -qanvars: on ee 
gavbes, Connected whan “Lhe whee. vevnforcement. Por Thor roots 
SUGh - srrongenente novarotiy ore NERS See she. Steseninotes 


GRELRS VOOT. == AS Anvemsus woy Ape, regordea the. genta nok 
with the cannection of he Tecelwing rod and the steel skelet=— ? 
OW, ven without a Veghtning stroke o ‘permanent: ouket, passage 
of electricity way 6c whose constant ‘Unf luence should, ee 
prevented. ; Cm i : Sat ee es cen 


(aisiesen te dade in which the ‘tension was aleay 40a, omen ea 

tae current being about 3,000 amperes (corresponding to 300,000 cae 

kilowatts). * The experiments ‘substentially confirmed the ner iy 

ults of Berndt (Darmstadt). Ruppel. ‘showed, ‘that the so-called — 

canal tease or ee ibn sickest ae, 3 SP ecaernwe conductor for = 

are aobiente Be ME ‘that the > Leguke tia. seeks to pass fone ss 

from the place strack by the shortest. ‘possible pata, etl follow 

ing metal to tne best earth point, and that all. destructive e 

étiects in jumping across are the smaller, the more the lignt- 

ning Can branch from tae point struct; for the” tore widely the i 

discharge passes downward, the weaker is its effect. it can © : 
popty be dangerous, where the current is concentrated. But by 

whe numerous embedded steel rods is primarily afforded a very. 

eteat possibility for. the division of the lightning stroke, 

For a small structure With eignt columns (each With 4 rods a= 


Zoi 
20 mm diameter, for eres there was at command a conducting: 
section of about 10,000 mu*, in contrast to 2x 50 = ik wp 
tor an ordinary lightning bepdieca e : : 
Note AePet1O. See Contra. 1943. pe 183; 1944, Bed3, CL, Th, 
BO. -- Further, Cante G. Bouw. 1918, 9.529 (VAGRtAANG stroke - 
on @ revaforced concrete mast, p.528 (Vidhtuing stroke on a er 
dZowed roof), Gvay Industrice, Beits. ABAL. Noe 110, | 
Likewise the experiments made by Berndt in Darmstadt (pet05) - 
permit with sufficient safety the conclusion, that for reinfor- 
ced concrete structures at least no greater damage fron ligat- 
ning exists taan for buildings of any other kind, and that re- 
intorced concrete construction as such does not have its bear- ee 
ing Capacity endangered by any ligbtning strokes oe 
¥. Treatment of the visible Surfaces, cee ae 
fae gray color of the concrete nas a wonotonous and cola a. 
pleasing: efiect, particularly when tae ‘en at surfaces are con- 
cerned, which generally appear. it the su faces are not +o. re- 
main a8 they come from the ordinary (unplaned) forms, then the 
necessary animation can result in different WAYSe | Ss oe 
Be Subdivision. of the. rough surface ‘of the concrete by bands: te as 
projecting some cm s with separate panel surfaces. (Grain of ee 
wood and joints of forms remain visible). 5 ie Se 


bs Use of planed forms (smoother visible ptitasas)e og a 

Ce Cement plastering. — | ares i gee ae ae Ace fe 

d. Gement plastering with later painting. (iates, Ce 
colored Sideresthen-bubrose, etc.). eee ey ee a ore 


e. Pacing concrete, unworked, treated with acid, ‘or wrought 
oy stonecutter, 5 RR ae Mga ase uaa ee ; 
f. Facing concrete, wrougnt by stonecutter and painted. aS 
€- Facing witn ashiars, tiles and the like. oo ae ee ee eee 
If the visible. ‘surfaces T} a the. atructure are yet ‘to be elabrs 2 g 
tered fos sake of better appearance, this is to be commenced — a Ske OO are ee te Ae 
DAE once after removal of the centering, In times ot frost: ea 
wrally all plastering work -- excepting of enclosed eons ee 
1s to be discontinued, 80 far S$ no means of protection irons 88 pes 
frost is employed, (See Section Iv. d). In summer, care is. $e ee 
o¢ taken for protection from direct sunsBine, and to wet Sie. Ste eS ace 
clastering more frequently after setting. The ‘thickness of Wata e 
the plastering is according to the . roughness of the surface, 
but is not to exceed dor had Cle 1 in all Baccus mast the § cons 


e 


10z 
concrete be roughea beforenana, cleaned nell from airt and ile 
kes wito wire brusaes ana carefully. washed, when possible with 
the aia of a 20 p. ¢. solution of muriatic acid, woicn must. the 
en be removed. by SUronge wasBing. Also advisable Ga rs ‘given case 
is a preliminary coating With thin cement milk. The. cement ples 
astering is to de firely applied e ang then. pressed with a rub- ee 
bing board and smootned, only when the concrete is ‘completely rae 
dried and hardened. If tne plastering ais to serve later as BE ie he one 
ound tor valuable paintings, it as. trequently. advisable before Ott ae , 
the application of the plaster to fasten a sligat mire ser oe us, ee, 
or expanded metal to the concrete. ‘Finally also nails alone ee oars 
suffice, that are driven in great number and act Like. ‘Pins. 3 Sk cee 2 
Tne plastering 1s to be protected. trou direct: sunspine and ‘kept 
constantly damp antil 1t is completely sete eee aes eon 
Kote 1. pelt, To prevent ony’ Back. of clearness: vn She locdaac eae 


wats, VV Ve Gdoisadle to state in the. estimate. the eosts==.prs- 
Ce Per we plastering as addaiivonal cost oft concrete. Otherwise aS 
special ovvention mst be calles, ANOt the thickness of ane . 
COncTrerte EVoen va She Grawing Va. to. be understood Os. without 


plastering, thot. thus ‘whe prastering Va not to be etd tor os 


ON SKTPG. =, a oe Cg Nagas bic ar ; ee 

NOte 2e Petki2. enanaee wockines: ov! ‘voughcosting | a ee 
{requently employed, The arrangement. consists- ot. by ‘porter wane 
ev, & Compressed OV woohine, and oO Mortar pump, wetch.are @r= 
\oen by 6 StTONE | wotor, rhe mortar wevng forces ‘Shrougin o eae. 
wWVDR NOBZLES UREer a. pressure of 4 A\e atmospheres, ond EMRE 
the war\ ~~ cetving Vs ‘gooted wVAh plaster. ae an hourly use 
i 2 10 8 w® of, mortar As. reckoned, one ean. cover 420. to ATO) 
n* of surface WV, plaster 4.5 ow tick. the phoster | sete nore 
rapaby and strongly than. plaster applied oy honda, & 

ROWS Se Oeil 2B, > another method consists An ‘alotaing the entire 
surface by Lnserted thin “stripe: Awto. ‘separate. vonels while Bone 
Cveting, these strips. being then renoved, ae plastering ¢ can 3 


, pb? 
£3, 


& 


When oodhere Wn. the. grooves. Abus | Fayneds cr. le Bilge wt See pte 28 eoieack 
Pe gooa mixture for cément plastering SRee, as cement. €: ce to Be Cea 

3 Sharp sand, applied ‘in two coats if possible, W1Lta whe. addi- 5) 

tion of some lime in the second. Coate One may also. use a ore ee 

cement-lime mortar (1 cement. + 1 lame + 5 to © sand) in case oe a 

of twice coating with casein’ colors, tluates, ‘etc. But in gen- ree 

eral lime mortar tor unaeteriee, is: siete to Men Pecommended, nS aaa 


OL 5 - 
MARU TB 
M Myth 5 ha 
aa? ’ WS ar , Pe Se f=. 
rans he be Medea 0.5), Cae ae Dine hee rr at ait 
"5. A Neat EK. oa Oi Resist 67, lg Ae ela oa 
ment ea ~ ‘ aor ety. t Sa ee Re eS Sa fh te # 
% : vo 4 - ¥ ' . i L 
ga + Wi de ne Wa ek es Ps ay eA vee x . 
BS Pav aherk on Se read i es +O Rie 
TAL wrt b ¥ 
; 
‘ 
¥ 


103. 

Ch plastering -- Wathout painting -- in consequence 
porous surface resists weatner less, ana aiso easily 
3 dirty. ; 
riace of tne cement plastering is always alkaline, i. 
sbted litmus paper is colored blue, wien pressed against 
nent witn a cork. If tne surface of tee cement plastering 
ated with Kebier’s Fluate until tne surface reacts acia, 

. uatil blue litmus paper*readens, and it finally one wasnt 
=. the Superiiuous salt with water, then the plastering 6 : 
be paintec in oil colors. + ine oii color will then adnere 
he plastering as well as on lime. ¢ } 
Move Ae Peis. OV colors musi not ve used on fresh cement 
Laster ing, since the cewent contains certain ACVAS, BWVTH whi- 
Rae OVW coors do not agree. iY one Goes nov use fl\uorates, 
“Ve recommended a pre\Vwinary ground of not Vinseed od | 
Wish. The oV\V cover is to be applied Ln two or three shin 
ts on. whe Gvived Linseed LL, each coat drying by Viself. 
© sonetines recommended 13 4 etic ty ot VE SATMeEnT 2 Lhe — 


... varytes sulphate, bvane-vlack, ochre, eX. On the 
SombAnation cf coloring matertals with cement, see Pe 2d. 

To produce G uniform ejffect im color o colored sand is pref- 
erred, Like Ulm ground stane. Colored cekents are to-.ve -treat- 
ed MVAN Great prudence. 

, It-is counted as a disadvantage to concrete ceilings, that 
tue plastering aaneres caaly, and scales off too easiiy. Tne 
Causes of tals bad condition are chieily tne tollowing:.-- Smo- 
4 -othness or dirty surfaces of the concrete, plastering too ricn, 
“ase ol Sand with particles of coal or unslakea lime, concrete 
« Still damp, aampness rising from tne ground, plastering dried 
%00 rapidly, effect of frost, airect eitect of wind and sunsn- 
: ine, etc. Particularly dampness forms the caief reason for for- 
z ation ot cracks in plastering. The water cenducts the salts 
(@ostly sodium sulphate or magnesia sulpnate) to the external 
) surface (efflorescence); the water Evaporates, and the salts 
 Pemaining expand tne external layer of concrete’ by increasing 

* its volume. ine separation of the salts is best impeaea by me- 


y . 


ales 
ropes 
Ores 


# 
-Toisn-ante paint blown on, or. even eRnpiee wate tee a mire 
‘brushes and dilute muriatic acid. gt ae gf Pace, . | 
‘In America the following treatment of visible surtaces has” 


een frequently adopted: ~~ the centering is removed after Bet 


“i 
a 
Be 
Re: 


“104 


Fon be made pester ‘ehe ‘Galipness: rising Tron tne éround. 


ie cracks, see. SoG ‘lee Sections VB and ‘RIL. 
© buildings of minor importance. or: yor baose designed to. 


= 


Bianca. on oaretal centering, and ‘only. planea centering is) 
ed. The ridges formed by. the jointing or. tae planks can be. 
off or nammerea off. If one wishes to do otherwise, then 


patee. but still before complete hardening or tne. concrete, has Cee 
‘the visicle surfaces are directly aiterward wasned mith water, 
ty washing is removed tae thin coating: ‘of cement, “bnat. -enclos- 
ed the grains of sand and gravel, SO. ‘that these are laid bare. 


The appearance of tne visiole surfaces thus vreated | naturally 
depends ¢ on. tne jboss OF ‘aggregate and its ‘duscrzbution: ‘on the 


cor inereasing the density. Likewise must. sufficient: ‘pro- 


@ Seon afar, and Std Mita, purely avalitarian icteric 


-Becommended a later. coating of the surtace With cement mith 
Ambite) wito a covering of yellowish-wnite lime paste or & he 


t daproe ot imieise. tz. properly’ done, then wita the. brosa’ a grate. 


D5 


be removed sce much» nértar, that a ‘strongly effective suriace rope Ak it 


Carance . 


iS produced, wnick tor buildings of: monumental sapertases ang . 


With bola forns 1s entirely an place. fror ligat and pleasing 
buildings tne effect of tac surtaces must be corre endingly . 
Hore graceful, whicenr cain * be brodaced - by the tie & 

Erained ageregate. Fig. 4 SHOWS @ Washed and brushed concrete 


suriace, consisting of 1; Portland cement phy 2 Pit sand + 3 sif-— 


bed Liver sand with 329 tT greins. (ine concrete a Ae eto 


on of small 


18s | 
consists of i cement + Z pit sana + 3 large wnite gravel). if 
une Nardening of tne Concrete nas alreaay proceeded too far, 
one would do best to dress tne surface wita a sharp busanammer, 
buen wasa it with allute muriatic acia ifi, finally carefully 
wasnlng tais off with water. 


TALS ‘proeedure indeed only refers to such structural members, 


Irom whnlcn toe forms can alreaay oe removed Witho&t risk, when 
even the concrete is not entireiy hardenea (walls, DanAUR ES: 
panels, 6UC.). 

At tne Breslau market nail cotn facing concrete ana plaster- 
ing were réjectea. Unplanea planks of equal wiatns, 1i possibile, 
used but once (concrete adueres too strongly to wooden planks). 
{ne visible surfaces first received a not entirely concealing — 
coatings of Limewasn color @nm concrete toné, ana tnen were Spr- 


inkled in & Somewhat darker tlnt to obtain 4 uniform appearance. | 


inen tollowed a simple painting in geometrjcal pabterns; but 
the grain of the wood remained visible. + =’ | 
Piller L.peilid. Contrvos. 19093. pe Sh. 
for facades, “retaining walls, ctridge abutments and the ie 
increasing approval is given to tne use of a special facing 
concrete, witn the later dressing of tne visidle surfaces by - 
a2 stonecutter, A lacing 1s 1naeed mors costly taan tne applica-- 
tLon Of acCla GeEscribed on & preceding page, out 1s essentially © 
more eifective. One avoids the cavities so easily occurring on 
wie visible surfaces (spots wnere tne filling mortar is lacki- 
ng betweem the stones); the repaired spots are always of a aif- 
feréat color. And tns plastering always nas the disadvantage, 
tnat 1t easily cnecks at a change of temperature, The facing 
nas a thickness of 5 to 12 cm, according to the massiveness oi 
woe structure concerned, must be made tolerably wet, tamped = 
hara, and 1s mixed witha a specially selected aggregate (asual- 
ly pecbles and rine crushed stone concrete i:3 to 1:6, in sone 
Cases W1tA tne aadition of colored fine ground stone). i AS @ 
rulé emphasis 18 laid on the use or s@ail erains. ¢ The cement 
containea -- aside Irom tne internal surface ~-- must not be & 
too great, since otnerwise hair cracks are to be feared later. 
lo still increase the importance of the facing concrete as a 
protection of tne ass against tne destructive efiects of wind 
and weatner, 1% 18 recommended to make a later application of 
Tlucrate to the dressed surfaces. 


Fowe-4. petits Hetn the se of Seaeg, . 


< 


166 | r 
Kote Le Pelid. With the use of gravel sand for the vvuilarng, 
Vt suffices under SOUS CONnGILLONS vo vewmove the coarse grains 
or also the. too ‘Fine 3anG from. the facing CONSCTSTe <= according | 2 
to the intended .coffeot of the Surface. One abso employs hy ee o8 
So-called vipp led | ‘Concrete (for exanpre, 4% Conant. ey sand a | 
2 pew gravel), waich Ls aneesed Voter. eo ea | 
KOte Be Pe 416. ne the concrete. ra Se the reinforces concrete a ae 
wemoers be quite fine. grained, then MOY ane OMVe © special Ra- 
cing Gancrere and have vhe sroncoutter avess the ‘surfaces, Vike | 
those of the ullaing. aoe s : | Hey es 
Generally valid. roles for: mixing proportions of facing’ eohty 
rete naturally cannot be. established. For use are particalarly = 
sultable crusned dolomite: and - basalt, WOite and gray granite, Pe : eae 
limestone and shell. limestone, “and | some mixtures used wita ee 
17 al are the following: eek : | oe PU SS elas 
1 cement .+ 1 sand + 3 fine ‘crusned stone (nips). 
1 cement + i basalt sana + 1. 3 crusned basalt (strong gray 
color with black spots). | prey ou uptake 
1 cement + 1.5 sand + i, 5. crusned ees cane (agos gray aston 
1 cement + 3 ground granite. (granite tone). ae eee Wwe 
1 cement + 4 sand + 4 crushed POPRRaTY +3 a Ule » mnie (200K 
like lime-tura). | | 
for tne placing of tne ‘facing concrete ‘is 


pe 


> best employed.a. 


ignt to a ates tamped ES and ‘socording to ele. 46 ote 
eed at 5 to 12 cm from the external. torm. in tis, way a mixtu- 
re of tne facing concrete with tne concrete nucleus benind he 
in tamping is prevented. After ‘completing a layer ‘of concrete, 
the facing concrete ‘is placed between tae. separating plate and 
tae external form to the. height of a@ tamped layer, the plate — 
1S &@gain drawn up and tne entire) layer is strongly banped at 
the same tine, including the facing concrete, ior ‘baat a -go0d 
Jugction between the two kinds of concrete is obtained, and a AMP ie h8e: 
later displacement of the tacing 1s not to be feared, if one ee i 
desires to obtain a special animation of tne visible surtaces, ORNs Ste ae 
then way be sitted and specially suitable pieces of, aggregate tn a eee 
de inserted and pressed against tae external form, In the Sate OR Ge 
er aressing of the waexbhe surfaces, such stones advantageous— ae 
iy appear. DA RUE ey oe ee Fa Pe ta 
Ine proper dressing. follows by the stonecutter aw the hana 


* B Y 


107 
pyc oneenenrs air bushnammer, + and inaeed after tne complete 

naracsngag of the Concrete. No o1ts of stone shoula break out, 

Slace tnen unsugotly holes woula occur. fo produce a Setter 

effect tne surfaces may be differently treated, partly. Dusohan- 

mered, partly: drovea, EUCee; CErtain portions may also be isit 

uncut, thuS remaining fougn from tne forms. ° 

Kote L.peiiT. Busnhawmmered, crondolled or pointed produce un- 

\forh\y animated surfaces, droving, fine or coarse striped sur- 

{aces. Sivuace by orcndaliing the angles are easbly oroken off, 

desssed surfaces -- for better ompecrance -- dre preferably 

prodyced with a tootn chisel (avafted margin). But generally 
tne surfaces are bushhanmered. 
kecently tne Sana clast is also used for aressing, whose ef- 
fect is to give the surfaces a unltormly rovgn appedrance. Tne 
sang ariven by compressea air Pen bataby eases the entire sur- 

tace like @ pointed nanuer. + e 

NOV? Lepeiis. & gana olost GPPGTaATUS Consists of. | 

1. Tae sand vast (the nose Veading the sand stream May ve 
up to 30 w Vn Vength. | | 

2. The compressor for producind the compressed air Larivoen 
Oy SLectrVG or venzine WOtor, OT LY eXVSTINe power. 

oe The avr Feservorir for receiving BAS GOVT. 

if one fas suployed colorea graveis ior tne tacing, toese 
can be washed with wire brushes. and dilute acia, ana allowed 
to appear. But thé surface must be weli wasnhea with pure water. 
it color be tixea with the facing concrete, then may only be 
uSéa Mineral colors, that are not affected by alkalies. Better 
1S tas use of ground stone in place of sand. 

Por polishing afterwards a preliminary selection of aggregate 
iS necessary under certain principles. the polishing is prece- - 
aca by a careful rubbing, in a Sliven Case by an electrically 
Griveén easily portable grinding machine. : 3 

jaustead of a. dressed facing concrete, also facings of ashlars, 
split stoné, of clay, marcle or porcelain tiles, may be taken 
\tor example, in bath nouses, corridors, etc.). It is always 
aavantageous, if the builaing material remains uncovered -- as 
in iacings -- since otnerwise the cconcretecannot be utilized 
in 1tS €ntire thickness -[or the supporting construction. bisaa- 
vantagcous 18 the alfrerence in tne elasticity under varying 
Stresses and changes of temperature. 


108 | ee 
for the Evangelical Garrison Church in Ulw the concrete gare OS ot ere 
ia es of tne interior are effectually animated by tne inlaying aa 
ue coljored clay tiles in the hammered dary gray facing ‘concr- 
ete (crushed basalt and fine pebbles). ‘Tne tiles nave holes # | 
whrougn ,bne pegs projecting on the back, borough woich were & ~ 
drawn fine wire anchors. fhe tiles were laid en the forn, fas-— ai 
tened in the proper place py. wires, then tamped over. + 
Note 1. PoliS. Reurts. EO Ze 1910. P.226. -- TO animate whe 
vistvobe surfaces: Siiaed WOPALCG pieces were also tamped an 
Artistically executed orhaiental slabs (for example ceiling — 
coffers)” Can be made in plaster noulds, afterwaras. being Set. ome ke 
Instead of being finished by a stonecutter suffices a ashing = 
witn acid. The underside of the dome of tne National Battle ee 
donument (with figure ornamentation) was coneretec on a apes : se 
plaster mould, but not worked over afterwards, only: improved — Le eae 
as far as necessary. a iueene i : : 
Purtner see B & B, 1938, p0230 (Treatment of the conerete S 
suriaces wita mica), “Artificial Stone Industry, A9iZ,. Nos. ey ae 
25 (Colored ornamental procedure for visible surfaces or oases 
rete), Gontribs. ° 4911, ‘Be 137, 147 (Architectural works: wita- a er 
lacing concrete), Industrial ‘architecture, 4914, Hett. Vil, = es % 
Vili (concrete and ceramics). purther see Cement & B, 1911, pS 
453; also Petry, “Dressed concrete asnlars: and artistic. reser: 3 ea 
ment of concrete.” pe MPa ae ae Moe | ey nee Se Sain oh 
G. Testing of Concrete (Cubes and enna ule abeegn ee or 
Note We Pohkie ‘This sreots. of tests wade pera commencem 
Went or Gurtvg the construction, | On Varer seats: of decyncentess sae 
Structures, see Section Av <. CN ee. RET ae ies secede 
Building officials are justited in. reguiring a best of the lta ig 
strength of the concrete; for according bo. What. Soe been sat 
ed O1 ps Shy the proportions of. mixture do. ‘now alone suifice | ; oe 
for deciding on the goodness of tae concrete, Since: now on tne ae ee es 
ground of the ministerial- decree, the tensile resistance ise. So 
Only considered under certain conditions ‘in the caleulation ot OR eS 
reinforced concret structures, the testing tirst: ‘extends to abe 
taining the resistance to Crushing. very. arrangement. for mak= oe, 
Ing tests, that must ‘serve for current supervision of. “the con~ : 
crete work, must be durable and strong, evén’ un er ‘pough treat- Nagy age 
meat, must wave small cost: of construction, | ‘giv sufficiently geal eye 
ccurate values dor ‘experiuents, be. Sia grt man ea | and portable; 


10y 
Pease allow testing on any structure by tne aida of laborers, 
ana take out litsle time for waking tne tests. if tnen all ta- - 
ese Conditions Gan in the main be satisfied only by tne dea . 
tester (#1£ebe 127), still until this time tne cuoe test fas. 
emalnea 6ubirely preaominant. 4 oe 

Kote 1. Hei120. The Hurriembera RailwoyRegubartion of pec. 19142, 
presorives tests of crushing with cubes and with cCOnvro\ beans 
For LVSNAVNGe 

i. tne Cube Test. 

pe ofticial regulations prescribe tne following: -- 

“io te glven ln the Gescription are tne origin and nature of 
Lhe materials to be employed for the concrete, the proportions — 
ot thelr mixture, the water aaded, as weil as tne resistance 
wo crusning abtainea cy tne# ouilcing materials taken rrou the 
cullaing site, and to be used tor the concrete, according to 
tne aforesaid proportions in mixing, after 25 aays on cubes of 
50 Gh Siaés. Ime crushing resistence is to be proved by exnid- 
it pefore beginning, at the orcer of the builaing officials. | 
Tne test blocks are to b€ marked with tne day of making, aesig- 
aatea cy a seal, and are to ce kept until nardenea as directea 
by the building officials.” , - 

Jaturaily these test cubes must tuliiy ana entirely correspond, 
Cotn in cowposition as well as in the Ooe oi aking, to tne | 
concrete of tue structure to be tested. The addition of water 
alone may b6 Somewhat jess. [ne taiiping must have the sane ex- 
penditure of force as on tae structural members. : : 

Tne 1ntefnal suritaces of tne ircn forms are to be previously 
olled; tne upper surface is to be made level and Sucota, wits 
neat cement, 12% possible. During the first aays the cubes are 

bigeas kept in¥molst air, protectéa from shocks ana sunsaine. 
it 1s recommended, that the test blocks be wetted once aaily 
at Least during the first eignot days, best sprinkled witn a 
sorinkling pot, or tnat tne blocks ce placea in wet sand. They 
wiil then after about 26 days be testsa Tor crushing resistance, + 
éltner on the burlding site or in an official testing laborat- 
ory, by means of a reliable press for concrete. The forms for 
tae cudes are to be kept at tne builaing site, always ready = 
Tor immediate use. Hor tne larger structures for each 100 1? 

of sacn sort of concrete wiil be mace i or 2 series of test . 
cubes, | 3 


Note 2. PotBO. Ouriert storage untrr suff{riorenrt horaening, as 


eS 


GOON estevliened: Oy experinents, tne shocks: Bir te 
ung of the concrete. Ancvease ite wesistances Quees.nove | 
token: directly, ‘agnor wakNag, for o Aietonce bas api 


a ther, +h 


i 4 


i Aah 
i Be cise 


he ‘Stondards tor. “souperotive <xpertacnts. on Aonpod ‘concrete, 


Von of BuVdings: ot vonped ‘consrete. ay 

Ii one desires to have: an re concrete. by a 
P23 

rials renee fabingenemshte ‘waen either Ba wen ebay 


16 
dea; 
ness. 


3a8 
4. 
a0 
ered 


Aen toate in. direction of ‘pamping = Speedie 
the testing of concrete’ only 26 agays old cannot show 
such a favorable result as if the concrete were 3 °. 
In general the resistance of ‘concrete at go and a1 

% Rai 3 
in the ratio af 3 to 4 (with a-ricn aixtare) or | 
a lean wixtere). After hk year the resistance isa 
as great as after 28 days. Bach’ Ss experiuents (“ke 
Slasticity of Gonerete. with ‘varied Additions of Wa : | so es ee 
Shown, that-an inorease of ec. oye 
noted after 6 yéars, and that only tne compressible. elasticity — ae 
(coefficient of extension) ais. reduced by age, Baca found for i Fieicn) 
concrete 6 years old, 1 coment #205, sand + 2.25 fine gravel op ae 


+ 3 coarse crusned stone, a resistance of 380 /eu’, With Se 


ts 


eng : ¢ ‘ ; : , 
faa 2 ; : ‘ SS : eee 


nee 


1ii at ie oe ie 
regard to tHe actual conditions of practice, it is | always, to Ss 
be greatly aesired, that an age of 90 days be prescribed ‘for 
test cubes, as the Regulations of the French government requi- ae 
re tor reinforced concrete structures, and as different techn- = = * 
cians have recommended, jen indeed wake tne opposition, that Segal 
after the course of three montas, the entire buliding i is: often 
already completed; yet the almost necessary paper ahd 
strengthening for bad results, ‘if not even in most cases, are. 
just as impossible after 28 as after 90 aays. if necessary ae eine Pas 
with unsatisfactory results of testing -- can a somewhat later eas 
removal of the forms and scaifold. ‘timbers be: required, ana pit ane ee 
nally also a pointing of the concrete. But depiner-tt“is. to Beis Gaye © 
considered, that when the computed live load ‘comes into effect, See See ee 
the concrete is: considerably olaer ‘than <6 gays. Ii one does Presa ie ong 
not wisn to delay the beginning of tne building, then ne may 
be satisfied by a ‘preliminary crushing test after 14 days, fen a 
ich is later Tollowed by tne final test after 90. Gays. (In Ham 
burg for daree buildings usually 2 to. dhe series of exp Paty sy 
with 5 cubes in each are required, corresponding to the 
ent parts of the structure. Indeed oe cubes a — 
/ dayasve aiter 28, and or airer ae or 90 days. 


LS ee 


1913-6 Y. 338. Fe wha 
A test of the cube ‘ingore, the bid, as. 


ina given case can ) only be aera oe | ose exist: ‘tor 


ae eel ot ony re hee 
ab aA 


voy 


b/s 


before the ‘contract. cle va ‘guite ere : 
or, tae work acne gt a useless re 
Re 


rally indertaae fever Sep ee pe : 
Tae crushing results of auttereas ube; 
Chaat ae wnerefore asa 


ae 


A tuoroughly uniforn ‘vauping 4 as very aegis 


b. 


LL 


value of cubes: ‘tests may ‘often be. of. a pa questionable mie ee 
ure, The heigat of fall of the tamper(25 to. 30m). is hard to. cee 
retain taroughoat, Auite aside from bhe fact, “chat one. also a ‘fe 
docs nolL. always” have: tO. do. wite a free fall of ‘the. tamper. oe Lhe 
aay Case it is not well possible: to harmonize ‘the pray ares. 
tne building with that on bhe cube, particularly wen steele . - 
reinforcement is. bhere- used, ‘since. the use of ordinary tampers 
is not generally admissible. ‘The usual dimensions of cubes. are 
witn 30 cm sides. ‘Sualler oubes(ot 20 em oF 10. om)» show greater 
resistances velues, a ‘Finaaly, Lb should ‘be. ‘mentioned ‘boat the 
test cubes snoula ‘not be. made in’ cold weather, since dering . 
the effect. of, freezing naturally occurs: but a “siignt ‘increase 
in the resistance ‘of: the concrete, and ait has” indeed been. ses 
erved, that the: ‘effect of freezing on the: lean mixture is. worse, 
as a rule, than- ror. richer mixtures. ; ee ee See 
XOt® 4. - A2S.. The Suisse Regulotions require: a series of ee 
cuves of 16 Gm.or priens of 36. oa AR x AZoM, the Vorter Boy “eS 
also be used for determining vesistance x0. tension by bending Pies 
vest, -= Bor smaller oubes: must aleo ‘be used” suoller Ghaingy 9 ae ale 
wherefore they cannot always be. termed suitable, An heh eae HL ee er 
easier and wore rapid preparation, ae A ea UI a sae ede 
The Tesivstance 49 CYUSRANG © dvainishes with. whe | earn 
dimensions of the. Cube, (see Arh. Bu MOAR. tie mea). ees. 
As determinative resistances to compression according, to. he. 
“general Regulations™(1908) for tas. construction ‘and testing 
of buildings: of tamped concrete are to be taken the. aide Values e 
of tae resistance values’ by ‘the maximum neigat of ‘the ‘manometer. A 
The actual neigat of the wanoneter doubtless gives a ‘mucn cle wea se * 
arer result for determining the resistance ‘Ot any sort of ae 
Crete, than tae beginning ‘of the formation of the first crack, hs 
(Wurtemberg wee Be Regulations, Dec. 1912), ‘since one at first ls ARS NR 
only has to do here. with the unimportant tlajing or splitting | ME 
of ‘the angles, first occasioned by tae irregularities of the .-— ae 
previously rough surfaces of the cube; it is ‘therefore abso a 
diificult to dgtermine ‘without error wae €xact beginning of. tere ey 
tne formation df a-orack. In taec compression tests in- sisevee: 
tories for testing taterials, the rough surface of the ‘ube is 
‘reviously made smooth witn cement or cement mortar, and ‘when Hai 
ground later. The eubes tamped at tae building site. ‘on the pole. | 
trary mostly come ia rough and unprepared condi tion ander tae. 


413 


Martens? press at the manufactory, 80 that already fron betore- Me 


hand <> it one. desires to: determine tire resistance: 40. erusbing — 
on the basis. of ‘bhe formation. of the’ ftiret crack Pisacd an untavor~ 


able result is’ to" be. expected. Toe: ‘oubes | are. tobe compressed oe 
until tae presaure . indicator of the. testing. machine snows a ie wee 


loss of ‘pressare, “thus. untid the. veplatance ef Fane epepeanaes 
body is haceae-* es ; 


ORs sometines: shears. eo Seeks a ie? resistance of a y | 
test cubes Lcoitert than, ‘he Econ of se conor an 


eater chan tne ‘resistance ot the: ene aa. fl besa, r 
ence is wade te ‘Regulation B for. crushing ‘experiments: on the 
construction of hacia of reinforced herent eis were * 


of water, a8 must deaheckiy a ation in iaetediépead eniees 
ve structures, in consequence ‘of its. preparation in bhe tigaw 
iron moulds: ‘impermeable by water, has. a suagter resistence ta 
an the sale Concrete mass, which loses. water. through “the wood- 
en forms and tne: joints contained ‘therein,’ # for. ‘the. test. ‘cubes 
also the conditions ape unfavorable, since already on acco 


wR 


of the great differences ‘or the mass, ‘the» jee pedis of thee ae 24 


ad 


cubes uhay”' be meee: “emcath Promudeeta< cues on: iia 


an iron fakin. BS ee t8 ‘also to be eee pean lag that ae 

tae iron forms the water contained in the ‘concrets ‘cannot ‘be S 
distributed in the masa, as’ ‘isi tne. ease. in ‘structural members — 
in the wooden forms. For also: one variable. depositing of. pen | 
concrete =~ sometimes with cand sometimes: without pressure: by 


ircumstance, that tae beginning of bhe hardening of ‘the conc~ 


reve (within the frst 24 nours) is varied, aad ‘indeed in eons 2 | 


Séquence of the unequal condition of. the cement. in sething oe oe 
the large -and small masses. And finally is: to. be rogns tanned 


ge Structural members ~~ as well as. to. ‘take ‘into account: the Ga niars 


wad 


Me aD Rm ea ar 
also” still phe ‘ampossibility of. ‘obtaining a similar hardening : 
procedure in the cube and in the “structure, since ‘the magni tan 
de of the upper. surface naturally ais” not. without influence: on 
the hardening procedure, | Professor Oller, Brunswick, states, 
that in 21s. experiments with eaves, De setoenae ‘tne elie 


bes. snould indeed serve. first.to. ‘attord ‘apparent: eens 
at the concrete was saepennsly made; Ls tae . 


er of the laborasoKien: ene especially comparative eae 
tests are undertkken with the use of, differant kinds: of aggre. 
gate and sees Also. there craps se! Pas uaa iemunacy: 


\Vstances ve concrete Va compression < obtained. ao Manatee: 
of T-bveans are about - ‘462 tO. we 25, and. for. saetncgaten bene 
are about 1,4 times the- pesistance of a SHBey og 

NOte Be Pe 4256 11% wos been Found ‘by experiments, Shot bet 
een the resistance of bVosks Bode with “the “wos exact Fanpins 
vy hand ond with tne Schmidt machine mo. aifference | existe. Ac. 
cording to the statement ot whe German Concrete : Anion and. AN . 
Union of the Portland cement Bonufacturees, such locks” wade. 
WVTH Bhe wew SChMmVat washine ore. ‘Aoken OS: sini Hs node. according ai 
the new offioiaV stondaras for comparative | oruahing. Seste with 
Tomped concrete. The wochine can. be employed woth for the: bex- x 
ermination of the actual Tesistance, as well as for. obtaining | is 
The vest mixing Proportions end. Aho. deat row wotertole, “indeed 
Yor cubes of 30, 20.0nd 40 om sides. d cube of 80 on As Sowped ea Shae 
With 218 blows An 8 Winutess ane rane ae WS STR eNO BS a 

WOVE SB, —psi25. Qu tests of Cubes, eee. further Section Nie Lor 

Yollowing is reproduced the regular report of a \ SPURL EE, FORh., | Beir ag 
&8 an example. Tera Sore ona ee 
Report of testing on. dane 19, : ashe, ain. ‘the Socheny of. the. acs ae hy 
essigned Firm, of PERteyng tests on | Wres vest cubes mito. tae pera B te ths 


od 
- 


ai 
i ii 


e415 . 3 
nuxture of 1:2.5:2.5 (concrete of crushed stone for piles and 
supporting ashlars), and three test cubes with Bixture 233; 5.: 
(Ggavel concrete tor foundations). > 
Rimensions, .30 % 30°%° 30 cis hia ipece Gatos 
Age; cubes 1:2.9:2.5, 52 days old; made Nov, 20, 4913. bes ME ieee 
@ubes 23:5, 39 days old; made Dec, 10, 1913. , 3 
Compression was applied Perpendicular to direction of vamping. 
Tests were made on machine of German Concrete pete a by 
system, and produced the following results, — 


i oa 


+ WiXeed2 20532.5-1 Maas a: Bes ates ca ca i 
No. of cube I Zi aS ita 4 a Ae rags 2 de ar aeons 
Hts in kil. 6248. 63.0 63.7 | 65,0. 65.5 S508 ee ae 
Comp. at first crack es 7 | if 2 ee 
in kilfom* + 268° 276 234.4163. 167 160 
Comp. at Highest manomelen pressure gl 
in kilfen* 0335 @By)  90Le | 194) 1882: 295% 


(wor cube I of mixture 1:2.5:2.5 the crushing resistance was 
not aetermined on account of first: Eyes the t maxinenacanne = | 
ity of thé machines). Be hcl 

Kote Sy by 126. The values of thle sertes avg olso. ee 
Wed. : ne oe CA te on + Sas 

As determinate crushing - veut bi ca: may be. baken ee ag 
or values for’crushing obtained by maximum heignts of sano | 
er, according to Geaeral Keguiations for preparing, construct= a ahteay 
ing and testing buildings of tanped concrete. (1908), thus be 


ing 307 ‘kil/em* Gor mixture 4:2.522.5. : pee pe a 
167 kilAeu* for mixture 1n$:5. Ng ger SAC Sar te . 


Dresden. dan. 49. i914, rar 


2, Tests of Beams, 

it la without doubt, that tae metaod of testing cubes of eOn~ 
crete fas Many disadvantages and soweces of error (use of hea- 
vy, costly, mea Gifficultgy portable Aydraulic presses, frequ- 
“Catly with not entirely reliable hasousters; lack ot watuenat- 
icedly plane surfaces, therefore no uniform distribution of 
pressure; ‘cost of transportatidn of: cubes; frequent delays in 
‘aking crushing tests in’ the laboratory). Gompréssion tests # 
With Concrete beams generally sive greater values for resista- 
Ace than tests of cubes, In pvery case must sufficient steel 
0€ 10 the tension gone of tue bean (about 4 PeCede Tae resulta 
‘according vo experiment® of Schiile) are toe wore regular, tne 


‘greater the dimensions are taken. The beam ' tests can ‘properly ee -s 
be recommended only for the determination ‘of rectangular: bea~ HER ths Weenie 
ms, in aly case also for slabs and ‘T-beams, but least for col- Bs CREE ee 
umns. The defects of all beam tests are the following: -- great- eal see 
er liability of the concrete beams to injuries (by rail trans- 
portation); Greater effect of size of grains and of talping; . | 
possibility of slipping of reinforcement; indeterminate | eit a BSoh eae 
ence of size of reinforcement: rods. eh | Pe nice ew iT 

Wote 1. pe 12%. Since the regulations: ate al). based oN. ee ek ey ie: 
resistance of cudves, experiments witn gone. cubes. Ot. Ane sone sap oe i 
Time Wust S\oe ot saute, {or caloulations. AGGOTGLNE vo. the | 
experiments of he German. gommission an Rervaforaad Concrete eo 
(Heft 12), the roto of she resistance to bending to nesist- 
ance of & cube was @ertermined as averaging 167. Tt was further 
determined, that the effect by the addition of water makes At- | ates tc 
seV{ Voportont, the ratro was 4.24 for earth-domp, 1.83 for. ee 
soft, and 1.58 far wet mixture. The experimenis showed in alt 
cases, that the beam test nay ve meee oe as @ did tate sal ae 
the ouee test. ; 

On tests of veous, see B& E,. A940, Bei h2, A9445- Re aa, 28h, 

SOR 495, 1942, pe 40, 213, 280. Arm, B. 4944, B. 44%) 151) PEI. 5 
263, WAZ, Be 2BG, 1913, pe LAB. Burther see Researches An do- 
Kartu Of Reinforces Conorete. Beft 14. Bwperdern, +4 Test of Qu- te Bee TY Be 
ality of Gononete)s Aym., Be 1918) Bs 4k3. Belts. &. Avch. u. PS, Aa 
Ings Union, 1942. p. 177, 282. gowtrivs. 1912. p. 55} 1944. paShs ea ae 
bei. von Bmperger’s Beam Yester (control beams) permits 4 rap- Odie Cte. 
ia test of tae quality at the building itself. Section ana Lene es ee 
ngth of the beam are found in Wigs. 47, 48. As loading in the nak oe 
maximum case 180 bricks (600 kil) came into consideration, pi- ae 
ied in 10 courses, and the concrete beam is loaded at two poi~ aie 
ots, The total cost of the necessary apparatus tor the bean ig a eg 
‘ester amounts to 250 marks. In this is not included the frame- 99 
WOrk represented, which is easily constructed/at each burlding x rs nae 
Site. (Cnoemical Laboratory for Clay Industries). berlin). ees 
Tne Reiorm festing Machine, patent of Buchnein & BGisuses’ RA oe 
#rankfort-o-M. likewise presents a simple and rapia making of 
a large series of experiments; witain 2 nours can be wade. Ae RAN 
bests Wltnout haste, The apparatus itself is snown in its ent : 
irety in Fig. 49. The beam is tested vertically; the. portion 
tested rewains free from transverse forces. Bottom and top hee 


ae Fore ae PRE 
levers are connected by a tension fod, whose length may be sh~ 
pile by turning a hand wheel, but to be able to measure the 
stress at any time, the tension rod does nov directly join bae 


top lever, but by tne insertie of a weighing lever, waiche tes 


quces tae stress in the tension rod to about 1/40, shown at + 
tne longer end. Here hangs, aa aluminium vessel, that ‘receives. 

water as 4 welgnt; after ee a cock, it’ runs into a vessel. 
connected with the bottom lever. Hence the increase in ‘load on 
the weighing lever is thus quict and. Gone fhe operator - 
nas only to take care -- by turning the nand wneel,’taat the . 

weighing Lever hangs«free, As soon as the test piece yields, 
tne weighing lever falls and automatically stops the apparatus. 
by Simply turning around the test piece, the same can first be 
tested for tension and then for compression. The wachine is @ 

packed in @ case ready for use; its weight amounts to about 150 


kil. Gost of the machine packed ready for. transportation 105Qmks. 


The test beams (according to Fig. 50) are 1 m long, 10 cm w 
widé and i2 cm aeep. Thus taney -are quite heavy. They are rein~ 
tormed by flat ‘bars, recovered after testing the piece., there- 
fore can be used permanently. The flats are curved in semicir- 
cles at the ends, taus forming botn top and bottom ends Stir- 
rups are autogenic welded. 

The capacity of the Reform festing Wachine extends GQ. ehout’ 
430 iil/en* resistance of tne beam, which saifices for most. 
practical purposes. fhe stress in the concrete corresponding 
to each load is found from Tables. + 

Kote Ly .pel®W See B& By LVL, pe BA, 1918, P. 38, 22, 38%, 
2204 Bonirvoe. 1942. pe 133, 


& 
pies 


aia. 8. oe eg EE 
SEOTION IV. CONSTRUCTION OF THB SOILDING. | Sa One a 
a, Arrenwenent of the Building Bites 4° ye 
First is concerned the most economical and most suitable ara 
rangement of tae, building site, and a ‘proper distribution. of 
all works of. construction, Wita corresponding congideration ae eS 
tne local eemereeraties of the ‘ground. First dust an uninterr- a 
apted procedure of the work be taken into considerbtion, sever~ Ror 
al beginning - places must be arranged tor great ‘building spaces, bed | 
so that the divided workifig groups may not disturb eaca otner, aah 
and €acn retain a suificient freedom of movement. Building Bas geek | 
eds are to be erected for tne superintendence and the monies, oo the 
as well as for the building tools, cement, etc. 2 ‘Then are hi 
be arranged places for storing scatfola timber, steel, sand, ines 
crushed stone and -- sheltered as mucn as possibie, working, G05 5s 
0 es and sneds for carpenters and steel men, + to lay OE ed see 
ter rails (narrow guage) from the terminal’ rails to the ee 
ing site; for the transportation of materials must be as cheap Css 
as possible. finally, care ts to be taken Gor water supply, for 
lighting tae building site, and for tae correct distribution eS Bie ae es 
of all machines. * The mixing machine is tobe so placed ae ae 5 ee 
‘possible, that -- according to the progress of the work -- ye ee — 
may require but suall branspor tation oi the concrete mass. fo. 
be considered also are dangers from fire. (See Pe 77)+ x 
NO%CS Ze De LAV. Ou Lhe constructvon of oO ‘HOrsOnhe shea. for 
COWEN, BEC Ze & Be 1808, Y- 642. 


~ 


Note 1.p-130, If one hos oF Command o . eye arranged qe oe 
taen the forws can be thus prepared. weforehand, Aen weing ee 


Vivered by railway, Otherwise must be arranged (or Varge works) — 
a temporary carpenter ahop, equipped win e\rouVvar BOW," “band ee 
san, evaning and vor ing WOCHVASS. pg itue! pote ee 

Note 2. BeisO. An the Larger owi bang: sites. An SOW cases -& 


Quite a anunber of machines ave employed, whose proper ETE 


nent for ab Vater owiLaring operations AS of he. greatest Vupe » 
Ortance.e AL erection oo the - Aras. Boctory an Steyr Was produced = 
\n one Gay over 1000 we of concrete, which agturally reguived S 
the avrangenent of a VETY Vargo buses of machines. = & BS. Sater 
Qe 48%), Gee a 

Sand, gravel and crusned stone, as a ene. are kept apart, . 
hBaped in bhe opén air, al pnough wetting by vain makes more & 
cifficult the determination of. the amount of water shat haees to. 
be added. 3 Pit ag i Oe 


419° 

Also see the suitable arrangement of a store and work yard 
for an exchange business of about 1,000,000. marks (storage of. 
abundant steél and wood equipment, as well as of steel macnin- es, Be ie 
ery ana forms tor local and foreign. oo Arn. Be 1944. ee 

Already during the erection | of ‘ey trekenis ae. the Terug: (Ore 
may test pieces be prepared and tested.tor strengta av ‘the. site Rie oko oe 
or at a neignboring laboratory for testing materials, it is ae eeae 
toen decided, waether tae sand and aggregate intended for use, 
as well as the designed mixing. bubaaed cere also correspond to 
tae actual requirements. Bist i ie BeBe 2 ty Cp oe GATee 

b. The Placing of the deamiedenite: de ee aE 

Fhe placing of the steel ' is. ‘preceded by the construction: of 

pe forms and framework . (seep. 76). The necessary errengenente 
or transmission are to be provided. Likewise the forms. for = eh 
chases (pipes, lighting fixtures) are to be properly seragine 
Grooves on tne surface of the floors must naturally ran in. the ea eae 
same direction as the bearing rods; see p. 158. eget, : ha eee e 

fhe steel reinforcement “is to be arrangedss® that its actual: ae on 
alstances apart correspond With the Calculated distances. bese a : 
is most simply attained by fixing the position of the steel = 
network on the centering at several points ‘by bits: of mortar, 
stones or small pieces of wood. + In using gravel and gue 
stone it 1s to be considered, that the stones can easily pass 
between the rods as well as between ‘bhese and. tne ‘centering, hee 
so that the Sa of the grains ‘corresponds. ‘During ‘tbe work Obs 
tamping must'occur no change in the position OL. ‘the ‘steel, ‘nor 
too great deflection, wherefore stirrups and supporting wires 
are employed, enclosed with them in the ‘concrete. On’ then anes 
Sultable tampers with claw-shaped plates, by weans of. which 2 
these readily pass between the sides of the separate stirrups, 
lae steel rods mast not lie too near the surface of the coner~ ee 
cle, Since then cracks can easily occar in this thin. external 
layer, and consequently tae fireproof covering” of the’ steel is” 
destroyed (ste p. 5). For columns are first set the vertical 
rods and then tne bands are inserted from above according to . 
whe progress of tne concreting. Fig. 51 shows an improper arrn 
angement “ bands; the distances a must be equal, and the 
0400s must Hot be oblique. (See Section xV). Great care is to 
be taken in the placing of the steel reinforcement for thin . 


pis 


dh 


. 120 * | a 
slabs. For if tne steel ‘in a slab 5-cm thick lies about 1 om his pe es 
too high, the supporting: capacity is reduced about a fourth. b Rg 
, Rove de podSle Very. gdvantogeous. ‘Tor girders Ore ‘SuOly) vonde bi Seat BOR ree 
of concrete about 2 om deep, & toh ow wide and 20 to 30 owe eee 
Youd, praced on the form at. aistances: Ot 20. AO 30. ow. Iron ate tite | 
rips Rowe the: Sisadvantage, thar whey show trrough and reduce ane 


hye: or okie an, S 


4 


rusty streaks. : Raa etn. a eens 
Phe details of the coingaspeneae mast. generally be represen 
sed in accerate general steel diagrams. por ordinary tloors x ~ aie, 
and plers are first executed ‘the. forms eitner. partially” or res 
pletely, the: reinforcement. is. gradually brougat to. “bhe desired - ES ela kete 
places, and the conerete is. tamped, Birst are tamped te piers 
and girders as far as. to’ the. underside of the floor, sadtea! ayc4 
are placed, the steel rods” for the ‘slabs: and ‘tamped ‘over. ‘the 
running planks Lor: bringing the concrete are simply laid on 2. 
toe centering far the floor. If the floor reinforcement: Pee 
uding the distribating rods) pe placed at the same time as the 
reinformemeats of the piers and setieny ‘then his creates 
nks must be raised. geting an vie ‘ LSP ca ee 
Qne may also first soustraet .the ‘eeatetiil and i place the “en: 
tire steel: reinforcement at the Same. ‘time, connected and. so ® 
wired together, as to produce a steel skeleton as ‘rigid as pos= 
sible, free from didplacement, enly then proceeding to ‘the pro- 
per work of tamping. In this manner -- previously preparing Be bi 
the steel skeleton on tue work yard, and at termards placing: ar 
tae ready wired parts in the form -- may be attained ae 1@APEr 7 
ing of the labor, an increase ‘in the progress of ag is 
and a greater certainty. Further. seep. 54. and B26 
Oe Plaaiee and ‘Tamping the Conere ves : 


occur in thé immediate vicinity of the waileise site, Ne ee i ese 
is 18 prepared by hand or machine . A tedious transportation — wh ja eae 
p ney unfavorably aifect the uniformity of ‘mixture by ‘the unavo- eae a 
* eable shaging. 1 the carrying of the conerete in hand ‘trays ae ee 

iS most advisable, yet in larger works is too expensive. Usual- 

ly occurs carrying with shovels, indeed just after wixings For 

greater areas must. be taken wheel barrows or dump Cars, that a 

are taken from the mixer to tne place of use. They can pola up a 
to 150 litres,and are provided with pulls in order to be di e~ a ee 
Ctly noistea on the building (without transfer to other budkets). 
in placing the conerete to be used, attention is also paid to 


stops at night. Only so much concrete must be prepared as can Sere ee 


actually be placed before stopping. Otherwise either the work’ 9 
is to be-carried on ta toe interval, or the remainig concrete. eee 
is to be excluded from furtner use. In warm and dry weather, - 


the concrets mass Suould BOL remain more tnan 1/2 to 4 hour > : a : 
before placing, or in cool and wet weatner not over i ha 2) ites) oa ae ae 
urs. A longer delay (up'to 4 to 6 hours is allowable only wikes Cte, th 


the use of corresponding precautions against drying. All cone= rae aes ek rai: 
rete not used a% once is to be shoveled over once’ before its ede Oh, at 
use later (only for subordinate purposes). Bringing with.tne 9 9 
shovel is not done by throwing, siuce the uniformity of the°. = = 
mixing would also suffer thereby. Likewise the concrete should) pb ce ee One 
not be dropped teo far, at most 2m; for greater heights it is’ si Selig ee 
accessary to lower it by spouts or buckets. Boxes with hinged ee ae 
cottoms are suploysd, -~ Tne less the taickness of tae layers, 
tae greater the strength of the concrete. Wor réiniorced conc- oars i 
rete buildings is taken 15 (to 20) cm thickness of layers. But © = — eek 
if taere bé no reinforcement, then without detriment one may = = : est 
20 vo layers 25 to 30.cm in theckness, for example in foundat~ | 
ions and walls. : | eee Pewee 
Note 1. p. 133. By experiments it has been actually determin— Oy. f 
ed, that by such transportation, in the soft concrete found in 
LAS upper .part.of. the wagon ~~ Coused by the shaking 7- water 
r\ses, the conereve venedth thus containing Less nater than & 


that sooue. La such cases o Vater Nie dataetetae Of the concrete nay 
LECOMS BESCSBSOTye ALSO Bee “Transport Gonorete,” POLsd. 

for structures, commercial buildings and werehouses, the cel- 
iar 1s sometimes utilized for setting the mixing machines and 

Pit other accessories ior mixing. Tus one 1s independent of. 

ail effects of weather, neither suffering from rain, cold -or 
leat. But usually the machine is placed directly beside the 
Oullding in a shed, protected from wind and weather. The hoist- 
ing of tae mixed concrete follows by heists and buckets, 1 the 
lurther transportation in the stories by wooden or iron wheel- 
oarrowS; link belt trays are not recommended, since concrete 
casily falls in the links, then hardens and may disturb the s 
Working. Hor widely extended areas portable wixers are best. 
Une utilizes all advantages of the locality as far as possible, 
NixeS at the higner places, so. that the Tull cars havé to tra- 
vél downward and the: empty ones upward, in tnis way facilitat- 


»./ps- 


422 
facilitating transportation and thus saving wages. ae 
Note 1s Por hoteting the finished concrete by O-hoist for wa- 
TEVVALS UNCLUGIRE driving the wixer. ane *s seams oowr - 20 to 
$O0\ 100. work por ue oft Gancrete. ; Ca ca 
In placing concrete in water sast Mises: ne preventea. bane wan 
shing out af the cement. The trench must. therefore be closed’ 
against flowing water, and ali. water pumps must stop during. ® 
the concreting. The sinking op the concrete sacks has to bee 
done with: suitable arrangements: (boxes, sacks and. directors), * 
Advisable is an addition of trass, to reduce the Washing out 
of tae cement. The concrete itself Hust oer be made- earta~daape 
(See p. 41).°¢ sé 3 
NOV?S QePotB4s Soe *#Portland comens anne ise use “Ln tidus 
VOns” 4 TH COVEON. 1949. Be 4255 Rd See 
If it concerns the making of a particularly great quantity 
of concrete for a longer period (at least a year), then» comes 
in question the arrangement. of a cable railway. One is in a 
endent of the Country, saves transport: laborers, avoids thee _ 
cost of new roads and the maintenance of streets, shortens tae 
Cullding period, and keeps off the ground and soil: of others. 


ihe cable railway can at the same time be wsed for the noisting 
and removal of soil, as well as for bringing the centering and 
framework, the steel skeleton, ete. Adolf Bleicaert & Co, Leip- 
zig-Gohlis, supply fixed cable cranes, #here a side movetent 
of theo cable is not possible, parallel HOving cable cranes sy 
wlth $idé movement: of one or two supports, radialiy movable © - 
cablé cranes, (Century Hall, Breslau. B & & i913. peOl. Swing 
ing cable cranes with fixed bases, in which the motor rope ad 
dé Hoved sidewise within ees ue Linits. + 

Hove Lop.t85. See Contribs. 1914, », 4335, 140, Arw B. AGLA. 
Oe 2%, OT, 

wagens in Hamburg has discovered a metnod, that makes it pos— 
Sible to transport ready prepared concrete (tae so-called tra- 
asport concrete) of a definite nature for long distances, then 
Using 1b With the best results. The distances over #hichn tae 
Concrete was taken were quite considerable, -in one case being 
1/7 kilometees by rail. fhe procedure by which’ Magens treats . 
hlS concrete is the following:-- a slow setting cement is used, 
1ts preliminary setting is delayed by cooling the materials 
oy cooling and shaking the mixed concrete. Cooling is done 


ana 
ang 


true * i 
Ss Warier | : oe 
POI a ON ii oi 
Ra oe oe 


+c 


by cold storage of the etaniabas by abundant abeinkiang’s wate | ts He RNS Gags 
water the working area ‘ip the vicinity of the mixers, thus by. Sear | ee 
its vaporigzation,- further with pigher: beuperatures. sige by cover— eR 
ing the concrete during transportation with damp’ ‘sail clotas, ies. wie 

jhe Concrete thus made. transportable, as several experiments 
of wae famburg fecunical Gixperimental Laboratory shon, is wilh 
usable afser: transportation for ‘several ‘hours, for ordinary <=: 
concrete works, and it is even more: ‘suitable tn aa concrete rec | 


eae S 


by unskilled conctractors at tne building site, he con 
is well and strongly shaken together and. ‘thereby produces 3 
denser mass in the building. fhis-shaking ‘hag ‘aided tne amps 
to a Certain extent. In all cases of transport: concn: ete : ad 
vantages for restricted: ‘Sites, worthy | of consideration. Yeu * Foe 
before such transport concrete is generally allowed for reint— bie 
orced concrete structures, thourough experiments: are required.* al 
NOC Ze Be Lobe Burtner, see “On Bests Of concrete Ram Saat | 
port Gonovertes” pours. Baus, Gontrios. AVLO. Pe reg EONS aan cian 
Burchartz stetes On. the ground of . ‘the experiments. mentioned, a ete 
that dy tronaportotion o separation ot whe wixture. cours, thot 
vo ord\nany concrete results an. average Ancvesse of oy Pace 
strength, ond thar one either abtains greater satetyy “or ‘ee! 8- 
PSCLALLY wVth ogeregate of crushed stone, one. Bad had seve. we oe 
of the cement. (EB & Be 1944, p. 245)- fi ENE SE 3 5 ON Es ee 
pl’ (ne frequently common mwetnod of distribution by gente for nee Siig ESD ae 
large buildings in america (gravity distribution) consists ia. ae ne 
this, that the fluid concrete mass. (cast concrete, see -p.42) © ee oe 
is conducted from a reserv@ir in an elevated aapiebineragion oe - 
er through pipes @nd spouts to the place of use by its own gr- 
avity. famping deés not occur. 4-fen laborers move the movable — 
ends of the Speuts to the required place Of use. Whether the See 
saué quality of concrete is obtained &S with us, certainly BD a 
pears questionable. Advantages of the method; rapidity of exe- 
cublon of the concstruction, saving in wages, in means of tran- 
Sportabion, cars, etc. Avoidance of snocks on completed strac- 
tural members, s@ving ‘in framework. Naturally the same equipn- 
cat may be employed gor different structures, + ) 
Note Le pel36. See Gontrivs. iSii, 5h 106. Avw. Be 1913. 9. 
Tie Gents @, Bawos 1912. be 6190" 
NOW Commences the tamping of the concrete until it saeats. * 
it the tamping is to be carried still further, then danger is 


incurred (especially with concrete too wet) of produethg: i ROP ED) hae se 
ening of the masa under the tampers, thereby disturbing tee Be aes 
setbing. With conctete too drp, the mass of stones influences 
tne effectiveness of the tools. Qnite particularly firm is to | CSG, 
be tamped the exterior of the member, since this is 0ST siteae 
sed in statical respects. Tne different tamped surfaces must es i 
overlap. Gare is also to be taken, that the larger bits of st- | ae 
one do not lie om the exterior of the structure, but are cover- ae eo ae 
cd by mortar on all sides, Tamping in time ia entirely objecte ~~ = = 
ionable. Generally the principle is rue: =~ the stronger tne Lo Rae ee 
tamping, the greater the strength, 2 But tne magni tude:of the. eight : 
oressure of the tamper depends on whether the ‘tamper is: @llow~ ca ae 
(SE sq tahh freely and on its weight, of whether the tamper in Pe Naso Tk 
talling receives an ampulse from te hand. Height of fall is USNS gay Sree areata 
about 20 to 30 Cm. In a@l cases the purpose of tauping is to 8 = 
bed the aggregate as closely as possible, and to make the spa~ Pee aims fae 
ces formed between its pieees as small as possibley PRS Sa 

Note Qs Pet36. According: %O .2arvier vraquirenents,. the. Sompine anes: 
of concrete Ln car thrdonp condition continued unt) water app- ed ete 
eared On the top aurftace. ‘TMS regulation is now owiitea Vn ie ie 
consequence of the use of wert concrete, Tomping « soft cancrete 
LOO Long Woy Result Ln Ghenging the WURTUTS « 

NOLS Se Pe lSSs BY VQRRSOT BEAL 216 vows gave avourt 50 se. & 
greater strength haw 64 with the same Force. 

Small vaults are |tamped if possible in tne direction of thre 
pressure curves, indeed in longitudinal strips, that commence 
at the abutments and are carried up to the vertex at top before 
‘the stop at evening. For dlat vaults it is scareely possible | eet 
for practical reasons to, tamp 1n the direction of the pressure | 
curves. [Ip any Case tare is to be taken always, that tae tamp- 
ca layers do not have the same direction as the internal forces, 
od that the strokes of the tamper do now displace the separa- 
te Layers. + 

NOVe Le PolBle Ou Laowmpiugs Ln strins for oriade vaults, ace 
Kersten, Avehed Bridges, 8 Ta edition, .p. 227, 

ihe tamping itself is done by the so-called tamping tools, 
that Consist of a generally iron plate wita rounded edges and. 
& handle fastened taereto. The size of the place«is arranged 
according to the strength of the conerete for the member treat- 
ca. best aré iron tampers with square place of 10 to 15 cm wide 


rey 
Wes 
i oe 
» > 


> e 


125 . 
and weighing 12 to 20 kil, Fig. 52). Bor tamping the external 
layers of Goncrete are suitably employed narrow réctangular. . 
olates to produce a particularly good tamping. For small anda 
sligotly reinforced structural members also light tampers of . 
about 3 to 7 kil weight are to be recommendea. For a closer 
arrangement of the steel reinforcement may be used with advan-~ 
tage neavy round rods with nook-shaped tamping ends; here is 


CLS ner va tamping of the wet concrete, To level the upper cour- 


se is treguently employed the concrete plank (also termed tam- 
cing plamk, etc.) with oblique nandle (Pig. 53; the laborer no 
ignger nesds to stand directly beside tne iron plate. Besides 


also comes into use the drawn plate. +" 


Piss 


Note 1eOeiSS. ALSO see the Hondouch. Yor. UW. Ps 1ST. 

for extensive factory use and iarge building sites, where 
tamping laborers may be continually busy if possible, recently 
the use of compressed air tampers finds anoreasing use. * Wn1- 
le a skilled laborer with an ordinary ‘bana ‘tamper makes: ‘about 
60 neavy strokes per mwinute, “he can witaout stress make 400 to 
600 strokes in the same time, But witb. ‘tbe increase ‘in ‘namber 
of strokes the force of the stroke diminisnes. ‘Pnese ‘Rampers” 
act in ay peat sien, vertical, sigue or aorizontal, fae well. 


foe number of strkes per minute oan eank eRe gule 
nandy air valve, ‘Tne laborer only needs” epee 


abby Meee ee ee oe to 30. wee jeRnasd 
ssuming a definite value ras Bisa eat 


nape <h tS 


out the hose winauataaat: ‘ne seati, wo 5 

of a nose supporter for connection of Bernas 
essor, in which the piston witn tne tampin ‘plate 
cidly to and fra, adjusted by a: valve, Furthen statements: are. 


tound in the “Pocket-Book for Use of Compressed aes ae 


ca by the Machine Snap ‘Cox, Prankiort-a-M, edition of 1914. 


Kote Be edhGs TNS iano <e: Seneeennte: GAT VER, Soe Beta sis 


\sts of;-- 


® A Compressor, ‘whe proper protucer of ‘We coupresses athe by 


4°: es : bi, x ? 


pager ; 
Oe ALT neseneewi shion motntoins equitioriun vetueen the em ens 
work and the use ii the necessary. compressed att. at whe a Require 
Ved Pressuree ~ ; Eee ug Petatow en oi Fea ee ane : ae 
c. The nose beading the coupressed, ios oO. hep proce. dE WEte pe ea : 
a. The proper working ‘tools ariven oy eonpresecd ee 
The cost of provve rng - Qa. compressed OAT equipment Kexclustve | 


of motor) for avourt 3 he Use. per: minute must amount: to ebeete. 


2000 marke. (gowpresson, veservoir, hose, heads, ond, S ‘ampere 2s 
Po wake V%S USe SCOnoMLGAaL Vt- 48 moturally edvisatve to woke 
the wiwost use possivte of the soleravly, Gear equipment and Fhe sak Mir Bs 
working tools, Qu cost of compressed oir equipment, see i & Be ie 
1910. pehi®, 590. Berton Leveungs AQI2.. KOs Be ae or ear Oe roe 
Note Le Dei SD- Opposed ve a: Aveadvantage, that An consent — 2 
ce of heavier Lamping, The wae On CONCTS LE mosses” As greater. : 
thon for bond tomping. To. wis oct. must, ovready oe. token into 
COnsVaeration Vn determining “the odditional Cost for concrete. RS 
work. See Gantribs. 1944. Be BA. ee ge erp en ee ae se 
Hollow masts and ‘pipes are receatly Gonntrucned anvekding’ to | 
toe casting process (Dyckerhoff & Widmann Co. bresden). ree 
procedure consists in using rotating forms, casting ia thin = 
iluia Gement worter mixaG witn asbestos. ‘Tne casting machine Me ere 
makes 300 to 1500 revolutions ber MEARE: according to ‘dimens~ age ae 
Lons of tne pipe. - | 3 aes i ae cap naee MT eh 
Note 2. See B& be 1943. ve BB “ares by 1808, rt 3850, 
pe 430, LBZ, Pe 26, 54033, pe BH. By Ba ae 
for furtaer construction on hardened concrete. (on, layers: ta- Oe sae ¢7 
at lie more than 24 hours), the old surface must be rougned hae eur 
with steel brooms, swept clean, wetted,and then coated witn ae 
bohin Cement paste directly before applying ‘pane nen comets 
it 1s also proper to tamp the new concrete witn special force An hee eae 
on be roughened surface, so that the union of the two masses. a eee 


way be intimate. Also it is advantageous to take for tne. first ts ea 
p/paet a rather wetter concrete or cement mortar he cement. +2 oS 


Ree 3 sand), a not ‘neak cement. Lin all ‘Cages 1b is well: ter 
carry On the ¢ astruction witnout long stops, 80. ‘phat. the aun ere eleiea i oe 
cer of joints in the layer may be as small as possible. ‘fre Hes ne 
layers must be made as fresnly as possible. Naturally such Ape eee 
verruptions are not to be avoided entirely; already the various: iy. 
stops aswell as tae ending of tae day’s work wake them neces- | 
sary. It is also appropriate ab ‘bhe beginning ot, a stop in the Pa orca y 
work, to cover the. sireies and horizontal surface of ‘the Liaderie i eae ak 


2 +e ! é ts phy iy, : by ine: 


cto wef seks, on Degioning gain to. ‘clean and wet it agein ee ae 
in a corresponding way, ‘before beginning to lay more ‘CONCretey — eS i 8 


4s 6 Pule ‘in buildings the beams are first ‘bamped end ‘baen the ea ae 
floor slabs; * bere ‘before all is advisable an abundant bias Sn ; 
cement of stirrups and ‘bends. ‘in rods. to. ‘comnecte ‘wogether tne 
slab and beam. in construction of. piers: suffices the extension _ R | 
of the ends of the lower reinforcement (about. 40 em) into the ke 
concrete of the upper pier (below). ith greater ‘lingtas of mo | 
ers, one can provide. ‘tor an accurate connection of both mite 
ces by stepping as ia: Fig. 55, ln a given ease. with: bhe use of Ss 2 ote 
special connecting reinforcement. Yet-at the end of the day’s Dee ee 
work aust always: be completed an entire’ tamped ‘layer, so far es : 
as no tensile st es” eccur there. Otnerwise statically pert-— 
ect separating joints are ‘#1 tnoUt importance, when. only compr— | 
ssile stresses) are found, that act perpendicular to te ieee = ie Sae 
ace, or waen pe reinforcements intersect the’ separating lage See fete 
ers, tor example as the- case for floor slabs. and ‘Ream as well aegis ess 
as for pierse Ain a zi ye : pe ee eee Hae 
Yote 1. psldQ. I% As else: advisable. to eaek: she. surface of 3B te Gia 
wae cCanctete with. ‘aVVute wuriatic OCid, and to Temove the od epee ea TE 


coating of cement, when thoroudhby woehing | Ort the acka with 


water, first treatend the surface BLK cement BULK. de ' aos ¥ 
NOLS? 2BeHetAD~. But whenever possvole, beans one Slavs shous ; 
ay. CORRSSTSG WLtHOUt ‘stopping. th gs ae te Ee te Bs 1x 
For a natural formation of divisions in tne. work are. uta epietes oo Ce 
enaea first of all the expansion joints. Be rer. ee ae Sc ee ee 
Kote Ls pelhle See Part Il. % th edition. p. 8. Seta Shae paeed 
d. Precautions against Frost and Heat. ge pak tea 


4itnough Portland cement of all aydraulic cements is least | 
Sensitive to tae iniluence of frost, ‘concreting in winter must a Mg 
still be dome with care, A long continued ‘period of freézing Ras Se eer 
(more so repetitions of snort periods of treezing). can only fie nes Sree 
injurious to concrete, woen the cement mortar bas not. yet set 
ana 18 too damp on top. That is changed into ice, for tae fre-~ 
SZing of tae necessary nyarating water way produce a. disinteg- Moa 
ration of the mass, * but in every case lengthens the times of 
vting and hardening; for cold retards and heat hastens the | 
Setting and hardening of concrese. Fhe resistance to crushing 
unger tae infiuence of frost is at first somewhat less than = 
lor protected concrete, bat already in about 90 days it atvtal- 


Page ae” ae 
Pe et 


© 


126 Be Soa Sr SNe ane eget 
attains pretty near the strength of ‘the Protected concrete. The 
resistance can only be greatly reduced, if tae frost acts on = re Re. 
éntirely iresa concrete. if this concerns thicker and more mas~ 
sive structural members, even greater freezing forms no direct. ee . 
danger. before all one snowld lengthen the time before removing 
forms, SO that the heat arising from hardening may be ‘etained, |” 
[n¢ wain thing is that the concrete nas time for later en ae 
ing in ordinary warm weather. Freezing & ‘has 20 injurious effect . 
on already nardened concrete. 

Yote 2. Pe 44. Vauardy the ‘consequences of a ‘sudden oaac) 


eb 


46 wot show Buch in. the. appearances for by the {reening AD ahe? eS ae pees 
DOr’ Yes COndined water Wid. the process: of setting be stopped. ae teed 

4 tewpercture of 0°G vengthens the setting period of the. ae 
nt to 3 or 4 times the ordinary setting period, ay AR Shows 2 
ag@avn, the concrete sets Further. Only alternating freezing me 
and thowrtag Vs not $008. ad Bxper iments Of. Burchortz showed 
that several hours of {reesing ava Ot essentially (OT feot Awe es 


hardening of mortar and concrete, but that Vong, continued hesita 
warterValby Gelayed the. ‘Progress fs hordeming, ond Andeed | 80 m= 

auch the more, the Vonger the effect. of Frost Vaated, Wth Nor eee 
ne CONntinued Trost, especially | for a Vean xbmiure, she fovora- uP oy 
vole effect of & greater addition of water, made Aneel tert wom tase Pies py 


hare aes 


re strangly than by @ short Aurotion of {reening, Sk ar 
PUT cs tet nie work with 5°to '10*..¢ x OL frost 18) to be forbidden, . 
it, no special precautions are taken. Yet if one must continue 
work in severe cold, -- to keep within the conctract: ‘bine for. Me ack eae 
completion, -- then (particularly ip bridge work) one’ can. pean ne 
ct construction sheds, whdch are to be warmed by stoves” day & 
and night. Under some conditions a covering of tne ‘spructure oe 
with sail-clotn. would sutfice. Phen the conerete | ih ‘nob: subjec- 
ted to stress too soon. iapareday) wseeter aye aust t never be do= 
ne ln freeging weather. | ‘ sy 


taken in dry EORPEN, paosecten ped the wind, by heating — 
water, sand and a égtegate before. using (up to. 40° | Cc), 4 then + ; 
limiting the addition of. water to @ minimum, and finally beets rks 
ecting the completed and. ‘vamped concrete by bad. conductors: BEN eae 
neat, like stram, bay, sail-clotn, sawdust, ‘sacks ‘of sand, Bt oe 5 
able manure, *, rotten leaves, etes, over tais | being laid. is ees 

Cloth, empty GORD: sacks | or tarreg Le aptar felt wtp ‘tambers— 


4 


a3 rec 4 at \ 
5 . ? 2y pr ae Poe ‘ . ; ae ¢ c 
-’ 4 ik - f AS : oA RS Ye ae 
: 4p Ken: ; Fs } " rege ie ese uh! 
” : big vn Rb oA 7 ¥ 1 aA ART A 1 Wess 5 43 x t 
- 5 > * 
¥ 
aad 


laid thereon =~ - fron the direct ettect of frost. But in ‘ne 7 ba 


mixed with bits ef ‘ice salt ‘sno, as well as: the pouring, on of 
bee cement mortar for ‘shortening tae ‘bime | of ha 
artificial heating ’ for une: same Riana bas -precantions 


cee pembers to be eee vactan are str ‘gual’ diabaateagy ‘ee 


are statically stressed ‘nigh; ‘economically ser y ase not as. 
injurious as loag ‘interruptions of tae work. ts ae 
Norte So For a Vesser. Gegree. of frost At Ae gonoratiy’ 


suff vovent 4o warn the worer ONye Cement | Ag heated. Anno. OBC. . 


HOC Zope LAs Muonure- Vs cspecvally £008 in consequence ot 


PLS OWN HOGT, yew direct vied: aa ts with ‘he concrete wet be 80 my a ea 


oVaeds * . ; 4 
Sometimes, s0 | far. as” 9 concerns | purely “banpeds concrete sure 
uctures, 2 to une. water tor the mortar is. added some common = 
salt {up to 20 DeCe solution): to accellerate ‘the setting, ‘but ae 
Mien gnder some ‘conditions# - May cause ‘efflorescence. + Better . 
is a smaller addition of soda or also. of Lime enloride. 2 450 @ 
os c. of the water added). Works during frost naturally - ~~ - 
ide from loss Gf time -~- ‘result in many ‘increases ‘in cost at 
tae ppocedure; removal: ‘ot snow, thawing the ice covering (wita 


salt). Breaking up and thawing the frozen humps” of gravel, ft 


all works that are to be previously accounted for ‘in the bid, 
as far as possible. Et is even recommended to. mix somewhat Tis 


cher in freezing weather, since then we: effect’ of frost is n ay 


not so unfavorable. Witha Bob: sufficiently rica mixture in a ss 
given case is advisable a previous coating of the steel wita 
cement milktpe 50)? -- - &iso po test. cubes are made in frost, SO. 


tar as by the building superintendent no OAR PES penntae: 4 sncresse 


of the hardening period is allowed. 


Note 1s. Pethde Bhe use of Sot ANS just as. sinple as echeupe 


hoourt o handful VS Taken {or SY Vives. of NGVET The water Boy 


be Warmed prevvously, SO thet Sea ads Sart aVesolues more quickly. 


Yor two SOULS SKVST. Sonetines. the - aboue Wentvoned effvoresce- 

NOE appears, a whitish exudation (wrongly termed - Smoasanry soi- 

petre*), TAS exudatron may be Tewoved by washing With o aviute 

solution of wuriatic acid and afterwards qhundantly .uith clear 
on socount 

wWoter. Pinaivy the , of tue BOVE Gonvained, the Goncrerte 

HeVEr LecoMes .entirery. OY, since av ‘salts absord mater +o! o. 


RreaY extents Further see B & Be ABLL. Pe B3- 


at 
At 


hte 


136 

Note Ze Pe Wer AS “KovV2vaum"™ Va the. trode. Burt an \ increasing — 
proportion of VW reduces the tensile strength of the Concrete, 
\ess SO the compressile. Vesistance, ALSO ‘he preparation aS 
the concrete ts made wore. aMiticult, ene 

Note Se pekhe According | to. the experiments | of Gerger (Gant=— 
yibse AVi4d, p. 155, 494), . coating the stee\ with GQBent Wik 
\aoreases the bond vesistance, thus the bearing ‘eopacity of © 
the ®Weeous +0 6 substantial degree im the REfecr of frost. Me- 
vely wetting the steed with woter alwost | entirely tebe eosin the 
vond VEesvstance during a frost of event BOYS e fen 

At the erection of. the Mountain Hotel in Sommerberg in the 
Black Forest, goncreving, Was even carried on at - ee AZ & 
1909. pe 275)6 ‘ 

in % & B, 1909; -p. 54, is mentioned a casein wnich Srost at gf Oa i aeres 
- 5° © was overcome by sStéam, so that it produced no- delay at. Dia ea? a OEY 
all. Scantlings were laid on the finisned concrete Ykoor and aes . 
covered with boards, so that over the concrete was a connected 
nollow spacé. Tne boards were then covered wita doubled sacks, 
and for 5 or © hours steam was introduced into the space by 
temporary piping from a steam engine. ‘The floor absorbed so .) 
uuch heat for its entire ‘thickness, that after removal ot tae © 
covering tae hardening ‘proceeded with extraordinary ‘papidity. She ae 

tae injurious effects of frost. may also ‘be otherwise recoga= 
1z60, in that bane contrete often sticks: to ‘the centering and ei pe 
pine surface shows cracks. Seca ge ab MRR Eas Rotana: na hi 

Pte not only the cold, but too great neat may inguriously Pelee ee 
affect saapod concrete. Warm weather sabeiatatey he hardening 


ge gerd ath ec pe 
occur in moderate weatner. & magn ‘degree of neat ee fh or 
evil as a result, 


er ‘ ss oe 


eae y. t Re fs 
trom the dubwis effect se tae ase | The ‘conerete is. “to be made 


cemént is prevented. Otnerwise | cement geaka or. ‘boards. are ‘Yaid. bce b 
over lt, which can Tetain the dampness for a considerable time. ee 

One also takes acconnt by ‘structural: arrangements. of tne. omnes i 

ges in volume of the combined members, ain ‘consequence ‘of. the. me 

Change in vemperature, tor ipxaap has: by Homies: eu tanason: “jens. | 


| -131~ | eink 
(movement joints), paakebad: by the insertion of uood, sheet = Pigs 
metal, roofing felt, 6tCy, and waich serve to aeeveny. expansi~ 
on cracks. * | ae ee a ha we Pia © Sager A 
qm Nove te pelbhe On the» construction | ‘and , arrangement of even 7 i 
exPpansvon JoUNts, | see ersten, ‘Relat. Bone. Fart. Tle pe 8, 
Aggording to all this, great-neat ‘by sunshine, a8 well as” 
great cold are iajurlous to. the settings. fhe best. seasons are Ca a ome 
spring and early autuma,” the worst being late autumn and wanter.? Ee 
NOte Zo Pelbhe gurther phe Rett we ‘of Publications of De ha pee 
AVAL. yest isecrsig: On, whe effect of cola. and heat on the Noma . . 
ening gapacrty of concrete); Gontevoas Aare, te aay, ‘Chey au 
ustries.Zevtung. 1912, oe. AMSe ees. Be ae Yate oy 
e. Removal ot Rentering and Forms. eee i 
aiver completion of the tamping ail shocks and vibrations a” : 
are to be kept away from tne. building, ‘Slignt vibrations during oe 
A Seutang are without ‘consequences. Tne concrete must ‘not be aa 
turbed and not be loaded with builaing materials or. the yeti | se 
olas of tae upper stories” before it is hardened, A frequent = eae Sh a a 
sprinkling with water in summer (for 8 to 10 days) accellerat~ bee 
es tae hardening. Likewise tne direct effect. of peavy gins eo 
must be prevented. furtner it is to be seen carefuliy, thagam © he 
holes and chases for the reception of cables and pipes BO. BRE 20S: 
torwed in places, that must siffer no weakening ‘on account, OR 7 aes 
important internal stresses. + Also one does not use the freso ee 
angle of the concrete in removing forms as a fulcrum for. am crow = Sube 
bar. fo avoid vibrations, instead of nails is recommended the ae 
wost extensive use of screws, bolts, clamps: and tae dike. eas 


Kote 1. peldd, AVso See Po 158. SSG Re Dose a wan: Ree ite TRE 


EY 


stg? 


ine correct tiwe for removal of centering « and Sora ‘Qerends se ey 
entirely on the goodness of the concrete, on the later cee oe ss 
of the structure, and not-for the least part on the ‘prevartane 5 
weather conditions. In autuma, days and nignts” are sie ee! 


concrete sets wore slowly, and tae period of hardening: does 4 
not pass so rapidly as in summer. bikewise the materials ab 

aclivery are colder than in summer, and also tne water; cold 

hours of tne night chill the concrete. All delays tae setting. 
of tae concrete, often in considerable measure, wherefore the. 
centering of the floors and vaults must remain longer in cold — | ps ‘ 
Weather to prevent acciacnts. 2 Gravel produces &@ concrete 30- , 
wewhat slower in fardening than crushed stone. This. abaclutely 


RCCSSSORY, thEt—oRe 


cL, eet 4 
a 


ar oe, 
> 
A 


+] 
cs 


age ee at ee 
necessary, that the removal of centering sould always be lefts eee? 
a skilled specialist or. foreman. for most accidents, that pain 
occurred in reinforced concrete ‘construction, are to be fefere gt oe 
Pied to a too. early removal, or to an improper ond Gnayesene Hie A 
rewoval. (See Be. 158).. me Ps es ae ve | geet: 
Kote 1. pel4d. It Vs wor always advisaole so. ‘woke the tote ; 
of removal Gepend aon the vate (Of wardening of a test wLoek of - ae 
Vike age (pe. 127), for. whe CORGLtLONS Of War dening ore of o . he Ee 
arviferent nature for own COSeS.— (Sectional aeeae oe atfecte | 


of wind, weather, etc. 
An early removal of the Gentering presents tae advantage’ ee te 

a quicker use again of the planks and timbers. ot the. pet 

but often results im the great disadvantage, toat in eonseque= 

nee of tnsufficient hardening of the concrete, changes: in the eee 

forms oi tne structural members. may occur. If “necessary, by a bie fone 

striking with a hammer or by scratching with a sharp wool, pee 

nay thereby become convinced, whetaer the rewoval Can be. begun. . MAN 
fre Prussian Regulations” prescribe:--_ Denny ei Seah ee ee 
“The removal of side forms. of beans, and of. ‘the forms for Ss 

supports, as well as the removal or tae centering of ue floor 

slabs, tust not occur before the dapse ot eight days, nor ‘that Terai 

of thé supporting forms of beams before the ‘passage of bhree a 

WECKS. + For greater spans- and dimensions of ‘sections, the ‘tine : 

is to be ipcranned to ‘Bix ponte under: some Conditions. — 


; AS 
Ps: 


that tae Pinaamieny? of the concrete is. s delayed pe Gitentns 
time is to be extended by. the duration of bhe ‘fros 

For buildings of several stories, the ‘supports ‘of tae. lower 
ceilings and beams are only to be removed, ecm tne hardening of 
‘Bae upper ones oe advanced 30 tar, that they” are able. to sup- 
port themselves. + In toe construction of walis. and iers in 
ouildings. of everal Stories, tne construction must ‘be commen 
ced in the: upper ‘story only after, saffifient. hardening: of these 
opahi ioe Sees members. in. the stories dying beneata 1b. a sense 


aes Fa : ; \ iy to ae ; bs : “ Ni t 
Kore Le De 148, Austrian Regulations requine ‘orovghout be ee 
weeks tine » fore the Temoval, (removed ot Acces sige embers) 


x hi ey wa 


433 
Suisse Reguiations wake. Ae sme dependent a vhe dead ot ene 


concenmed, Gnd. apecitys-= t et ns 4 

: 40 days for syons. up wala Coe Sees Oe le 
29. days for ayans we to ee Se aan Ses, Aor 
30 days or spans: over 6 Ws vane es Inyo pee a oe ite & 

Kon-suppor ting centering cimoers. (svae. forns ot beans) may | ae 

be removed .garbrer. Lofrtes ‘bout. 3 to es Gaye). ‘The. qloor of on. a Race 

upper Stony, as o principe, . should ‘only ve. Aomped aynen denooth 

L% exist Wo ‘SoMplere {voor centerings, unless: the Aew {oor | 

converting tests on the ground Or. On oe similarly. Fieri, baer 


sonry }% for a {voor wader. construction transmits nov" Only whe ae ee 
werent, but aed the shocks connected with the. Aompings -- “Kot ‘s : Ey : 
al\ the supports of.- o girder. Ore. to ee veuoued ot “Once, out a | ae ema 
sradually, even tf the girder ne. TwiWy ‘hardened, already. Bor oe “2, 
owiVGineas Wa severa\ stories, the removal of ane supports Ore: <: as ei 
aode {rom above downword, as a rule. kee Kore. ON Pe Be on oa a ee 
Note Le PeiATse Every. {voor {row which whe sentering V3 ewo- Loy em eee 
ved Wust be LN Condition to vecetwe. tne Load. - of ‘the recently — 
constructed floor Lying above Vt with sufficient safety. ae 1s 
oa0rv9e0. to vnegin First with. the removal of the centering of the | 
\ower fLoor ocaly when the hardenvnd of - the | wpper f\oor as Boer 8 
gvessed so far, HOt Vs can support piself. See Korte On Pe the. 
“Tae sejuence of work in removing tne centering or an ordinary 
floor 18:3 -- assuming favorabie conditions of weavher -- Sao 
ally tne tollowiné: « : | SES 
In 5 to & days:-- removal of forms of supports; ee ‘loosening 
wedges of the floor struts and removal of these strats; remoy- Sis 3 
al of top and side forums of cross and main ‘beams; ts renewed Ve Cos 
placing of some necessary struts under middle of ‘thoor asin oe 
Fig. 56 (so far as tne floors of a building in ‘several stories — 
must be loaded early. 4 ee Pe ces : case 
Kote 2epeih7%. The angles of | fresh: eoncrete, at Veast Vn vhe 
\Vower parts, must be protected agavnet Anjurtes. of 3 kinds 
vy Special Govering voaras. Sa ERS cae e | 
Note? Sepeith?. Bhe side forns Bg. beans and supports. Gan treo- 
Vently be Nepoved earbienr, oseuntng, Sut {iovent nordoning a 


oo \ 

"he i Rios SRG ay: te Y 
te oe te 

Mes 


whe cancrete. 2 

Note Ae De 4472 If The just qinisned ‘Topre mest ee eas sar 
ouV\a\ng matervals, then are enployed property Sonneoted wok 
Vad plonks, tO avord BLLOTATVONS 6° ern 1a Os 


my 


2. ia 


134 3 
In damp weather, in coeld’or wits pabtialiv preventea access 
of air, under some conditions twice as mach or more time igs — 
necessary.e All removai of centering occurs in panels, beginning | 
at tne wall. Teen more with tne lever than with striking tools . 
(hammer, sledge) tne wedges under the struts (Fig. 35) are to £ 
ve loosened very, carefully. The time for removal bust be larger, 
the greater the aikicweas between supports, and tne dead welgnt — 
of tne floor, a8 well as tae stresses ‘1a the structural pees e 
ini Great frame and vaultea siructures, briages and the like | 
cannot be cleared of forms frequently before 5 or 6 weeks. 
f. Superintendence and Acceptance of tne beibaanegis (Test 
Loaas on completed Portions). 


Sowe of the most important problems for tne losal superinten~ a a 


dent are the following: -- 
Suitable arrangemceat of the building site. 
Oversignt of the acceptance and storage of boildins naterials, 
especial jy ot cement, storage of steel by kinds and  lengtas, and | 
checking by hei a ae ase * 
Testing steel by; ‘bending it necessary ‘Yer to supply dealer). 
Suitable distribution of work according to plan of concreting. 
Selection of suitable foreman for the pesca? oe 
borers Sent 
gaseupeeeae of centering and forms, mixing and placing concrete, 
olacing of steel reiniormement, removal of centering, etey: 
Keeping a journal with statement of gaily work undertaken, — 
time of construction, removal of forms, daily Veneere wares ae 
oi Irost and rain, etc. Beh er 
Tae local superintendent must- be in permanent pelanieal nitn 
the supervising engineer (telephone connection cetween the pA oe 
ilding sive and tne business office of contractor is quite Pro om 
per tor larger buildings; as must always be at tae place; ae 
change in superintendent is to be avoided. Tae supervising ena; 
cSineer nas to frequently visit the building and to go through 
all building plans with the local superintendent (p.158). Nat-— 
urally tne local superintéenaent must be instructed concerning 
all exchange of letters and conversations of tae supervising 
engineer with tae owners of the building. ee. 
kellaole archives are.formed, that among other things conta~ 
1n exact statements on the assumptions in calculations, mixing 
croportions, and on the concealed steel reiniorcewents, $0 that 
later for alterations ana extensions, even aiter a long billie 


| apo 

way be found reliable adta, oO : 

PMT a well based assumption exists, that defects are- contained 
in the completed structure, which reduce the required bearing © 
capacity in consequence of later influences, the building off-— 
icials may decide a local testing to be required. Ef: design and 
construction under intelligent oversignt entirely correspond 
to tne official regulations, the detailed and costly 4 west 
loadings are properly necessary only. in bridge construction a 
ana not in buildings, in any case only WhED sligatly vested a 
architectural forms are concerned, Test loadings and measure- 
nents of deflections are and remain tolerably mornahona: as a 


stanaard of the quality of the concrete conestruction. ~ Far ee 


wore 1mportant is a. conscientious “superintendence and a pilose 
ent testing of Cubes and beams. (p. 119). . ait 
Note 169-149. The cost of the Loading test, shat foneraviy” 7 
wae contractor must vear, nae VA Oo Suitaole proportion %o- : 
the total cost of canstructian of the PEPE ERR RY ot most reach- 
‘ng about 1 PoC. Of The Contract price. — ee 
Kote BepethD. I% shoulda not ve omitied, that such loading 
Lest easily results in overstressing the OULVarng. aero 
UNG WOY OOGASVEN » MOVE CYAGKS. (the requirements of the Boviuoy ae 
Direction at Berlin soeak of *actual® oracks in contrast to i 
the so7calbed hardening or air cracks). -- One should never 
attirVyVoute too great Vaportance tO Ane ro fine cracks; 30° 
for as they Go not become Larger (oy adding or removing vonds), 
they ore wWVtRout VWaportance for the Keasistance of the CONCTSLS 
Naturally they enowve WOX WIVGeN, so that the re\nforcenent, As. | 
vored. Reinforced concrete structures without fine cracks en or 
the surface are generally but seldon Found. Experiments Rove 
shown, thas the number of cracks way inorease, Vf the sone cr- 
OSS Seotion Of stees is composed of 0 oreater wuwoer of smaly- 
er YOaS, even VT the steel hos voudsh surfaces, Since then the 
CONCTSTS? COOPEFates Wore VN workiWag togerher. B& Be 1208. ve 
17, 263, 275, 302, Av. Be 1909, p. 232, 30, 60, ye SPS 
It loading tests are not to be omltted, then the requirement 
of 45 days’ bardenihg is to be taken as tue least requirement. — 
veciaedly better 1s 9O daps’ hardening, as whe French Regulat- 
10nS providé. Otherwise one is dependent in this point on tne 
progress of tae pbuilding. : 
Oa load tests of entire Iioor panels and beams, tne following 
18 prescrioéed in tae Prussian Regulations: -- 


a¥ 


“~ 


136 

“In loading floor slabs and beams, if g = dead load and p= Ep se Bes 
uniformly distributed live load, the loading shall not exceed oem 
0.5 8,= 165 pe With live loads greater than 1000 wi /u* may be ein 
wade PeduGtions to the simple live lead.” ek See 
P'S", scording to the “Pr@liminary Principles,” which in many res eae oe 
pects were taken as a model In tae revision of- the. new Prussian CYS | eae 
Regulations, the loading must not exceed 0.8 6 $248 vs 1 (With ) 

a slab 10 cm thick and a live load of 500 kil /pe, according to 
tae official requirements, the loading p = 0,5 * 0.10. + 2400 ra Peery 
+145 * 500 = = 870 kil/we, and according to tae Preliminary Pre: 5) ay. 
inciples p = 0.8 * 0.10 * 2400 + 1.8 x ;00 = $092 kil/m*),: Very. aces 
proper 1s the reduction for live loads. sreater than 1000 kil/u4, eae ae 
since otherwise for sucn a loading unusual loading,masses would 
be required, and tne loading test might become dangerous. One SR a 
must first of all avoid exceeding the elastic Limit: of the st- eae. 
eel by the stress in it (about 1800 kil/em*). Wor economizing 
cost the ceiling of. the cellar will be chosen for the loading ane ba et ee. 
test of a building of several’ stories, ‘since there the mass: sate a gee 

the loading can be more: “gual and AAR eee | ace 


ting work nov connected with inthe ce ot oe Bey : 
Swiss Regulations. Live ‘ood thn AGS Pee (Uitkewtse te a , 
Bngvvsen ond Danish Reguvations), bie oe Re Oe ee 


Prench Resulattane, bie Youd ieee Ave 
wise Tonaerins Mes euneenens: is 


ations, - parse seve. WE OG 
ground, ae sreenten fo ' 


On test loadings on 
in prescribed. aoe 


199 . 
nidadle af tne floor, whose lengta equals tne span width, and 
whose width is one-third the span, but at lgast i wm. The load— 
ing spall not exceed g + 2 P. As dead load 1s taken all the 
¢tructural parts intended for. tae construction of the ceiling © at 
and floor, as live load the ‘increased values in Section WWliGei 
The usual loading tests are based. on the fact, that any frac- 
ture is preceded by an elastic change ot form, by a deflection 
for floors ana beans, If now this elastic change be accurately 
determined by the loading test, then may one deduce a conclus- 
lon in Regard to tae resistance of tne part of the building & 
concerned. - The loading test itself is made by piling steel .. 
bars, bricks, sacks of: cement or sand (eaca weigating 50 to 70. 
kil}, if possible on a layer of sand 5 to 10 ch thick to dist— Reereyoes hh Be 
ribute the load ane One way also use steel tanks, erad-— SAS Cee ee 
ually filled with water. * Bricks must not be boaded; festaad' os Cea 
of & uniform loading, the live joading may arch over the floor, Bes” oe 
and tae greater part of the load act directly on the supports. ee Rt wats 
Better than @ uniform distribubtioa of the loading is tue arran- ae es Ree aee 
genent of tae two concentrated loads. near the widdle of tae # z ty 
floor. Simplest is naturally a single load at the middle of ik Supe ae, 
tae beam; only half the loading is required. for tae use of ae, 
rolled beams, it is preferable to place steel rollers between a 
tae end bearings of the beau to ayoid any fixing. SE gh ag Pe ope 
Nove 1. PeiSi. Yet the amount of deflection depends. La a cers On ae ee 
Vain Gedree on the DeRONgement | ef the relnforcenant (whether One Socae 
with or without stirrups, with or without bends, etcsde eee oe) 
bei thus present wo OOTTOOR. dota aon be pt ckc ate vi a 


the structural. sae oubateynate: stresses exter, wea aery 
Wuck wat uence. whe: macros 0 be see ae 


are to be | eee a aeaate 


Aine crackseorres 


the Last apt the 


136 
itself must be graduated as finely as possible, so that one m 
may be able to estimate fiftietns of a mm. This 1s so construc~ 


tea, that each movement is transferred by a spring or thin wire 
and 18 indicated at a greatly enlarged scale. Some indicators = ~~ 


can only be used in rooms protected from wind, while others 

can also be used in the moving open air. Often vertical scales 
suitice, which may be ocserved through 4 telescope. #& The de~ 
tlections produced in reinforced concrete memb¢rs by the load- — 
ing are generally less taan those that occur in steel structu- 
res of the same strength ahd similar neight of construction. Z 
Some rules decide the mouth t of aeflection as the indication — 
of the goodness of the structure. 3 But since it is difficult. 
to compute the deflection free from objections, such a aeteri- 


ination can only fulfil its purpose, 1f the load remains a lon- 


ser tlme on the fbhoor, ana yet no increase of the existing de- ; 
tlection occurs, or if the deflection entirely disappears after 
removel of tas loading. pea ie 
Note 1. He152. The Loading way rewarn at Least 24 Noprs On 
the floor. The reading of The apparatus Vs then properly wader == 
a, vejyore tae Vooding, ©, WmmedrVately after Loading,.c, just 
vefore commencing Vs removal, &, some hours afrter the vewovals 
Burt advisabbe Vs also the addition of Vartermedrvate VTLUES. 
Note Se Poidee Inf St|ev vuraGinas, the Liwite for permissible 
deflection ava fixed as a rule, they vary between 4\500 ana 1\ 
1000 of tne free Length. In reinforced concrete structures th- 
23e@ values vary vetneen 1\1500 and 1\3000 of the free Vengtne 
Kote Sep-154.5. Thus the Hungarian Reguloatrons: - areatest per- 
Wanent = 1\3 waxiauw wef lection (a very wild rule). The Aust-—. 
rLOn Regulatvons require the same, besides accoraine to these 
rules, the coserved elastre deflections must not exceed oy wore 
THAW 2O PeSGe THOSe COMPUted Gor the effect of the test Voud ing. 
The Prussian Regulations of 1907 fortunately prescrvoe nothing. 
As an example of a measuring apparatus is mentioned the aei— 
lection measurer, Griot’s pabent (fingineering Office of Griot, 
Zirica). Wita toils results tae measurement of tne rise or iabl 
oy the ala ot an ordinary steel wire 1/2 to 2 mm diameter, suca 
aS way oe obtalnea from any haraware store. After fastening & 
Wee upper ena to tae undersiae of the floor, the wore is stre- 
icoed by a suspended weignt (brick or piece oi iron) of about 
< kil. It is then fixed on a s@lia base at the Gesired neignt 


Dv fs 


. 139 oie 
of abservation and 18 so connected with the stretcned wire, + 
boat the latter lies between two rollers of aluminium bronze 
as hard as steel and is tangent to toem. (Fig. 57). Griot’s-m= 
deflection measurer is aiso adapted for sidewise bending of 
supports. RFig. 58). bs . : ; 
Among otner flexure measurers are Wartens’ -WLrror apparatus, 
tne th xure indicator of Osske, Bauschinger’ s beictarat id 3 Prook- 
el’s ipdicator, etc. . 
Ii ohe aas a floor construction like FIle. 22 to examine una- 
ér the requirea ‘loading, then. Mast be measured: -- 
AU a the deflection of the floor. 
At b the. deflection ot tne stialler beams. 
At c the’ deflection of the main girder. 
At a tac flexure or bending of the supports. a 
Note 1. peid3. But i Vs to ve considered, that the et iect-— Ear 
Lon Getermined at b glBeady contains a part of that produced ee 
at GO. Finally, V is not to be Fonsekeeny) teat a compression 
of the soi Boy CooUr wnaer 4a, : 4 te 
ror specially constructed test pieces Gin ot Peak, ete.) 
tne loading is to be carried to breaking; tnen from tae ratio 
Piet the breaking load to the bearing capacity of tne floor may 
conclusions be deduced witn reference to sufficient safety. - 
Gikewise nere also are the deflections at the different seoti= 
ons of the test piece are to be measured and drawn. t But as pa 
a standard for tne ‘quality and ‘bearing capacity cannot be pecans 


en the occurrence of the first ¢rack; for ab “alone is. determin 


ative of satetpfagainst breaking. 2 es ea ae 

Note A. Detdh. A\so | ‘see Mbouding Lest. of a saka Waice iia ae 
Bisenoetans. 120%. pe 229, Gontrids, AQI2. pe TS. BuVaing offt- | 
ovals can Were make the permit Gependent on. the: ee 


vious tests and. Vood wg . experiments, ‘The ‘Voosing expertaente 
are to be carrted to preaking. eahees eg Depa ete 
Bor Loading - Aests. aie) fracture, | LHe. sum of she yonasatersgs Oh 
\oud and the applied Vooding wast. ot ‘Veast equcl. Swreefova, whe. pee cine 
Sum of the Bead ‘Vooa and the Rea id a Voade (setes Bete 


ulations). 


Ot ; 
cs 


Ra Bee's ae 


oe be r ae ee Rae “ - ass . : ase . : : my 


The Loud producing fracture. ust at. Vesat, correspond 10 three 
times the Vine Voad. . + twice | % 
WEWRSY .+9 Tar ice the other seen ‘Vosaing. (austrian Bessel: 

Kore 2 PeiSh, The Wurtenne 


oe 
- 
Oe 


oe aa : 


bead: Voad of whe supporting w a ce 


: | i140 

presorvoe for weams made in a factory, *thai the vrecking \oaa 
on test preces shal\ be 51a +9). : 

The aeflections can also be computed approximately, inaeca 
according to uae equation ot the elastic curve. Waking .) and . 
I constant, tnen finally results tne deflection: -— 

ee, oe 
oe oe 

This formula thus corresponds to tne distribution of tne 

stresses in a nomogeneous body. is ee 4 
| | Uniform load @| Load @ at middle|, 

Beam with enas suppor bea m @ 5/884 n = 1/48 figs Oe 


Beam, one end fixed m = 3/684 m = 5/684 i 
Beau, both ends fixed m= 1/984 |m=i/dog | at, 
peam cantilever m= 1/6 * |m=i/6 ™& Q@ at ena. 

1 = span in Ci. es ae 

i, = 146,000 kil/em* (neglecting tension in concrete) « Sect. VII 

mais ' © 3 bs tee ee ey 
Ip = woment of inertia of conceete compression ZONE. ‘She 
I, = moment of inertia of priser section about zero line. 


Norte Pe 155. The formula \s vased on freely supported onde 
of the beawe For cowplete Fixing Vt is to be multiplied by 1\5; 
for wolf Fixings vy 3\5~. Por aeriwartion of formula, see B & Be 
1208. pe 225-6 | ‘ zoe epee 

Since the tensile participation of tne concrete is neglectea, 
(but which assumption is first true when tne elastic Limb (OL: 
the steel is approximately reached; see Section VIII a)., ne 

actual deflections are generally smaller than those computed. , 
irdeto calculation oi tne actually existing statical par- 
ticipation of the aajacent parts of the portion of tne struct- 
ure selected for testing is neglected. For a uniformly distri- 
buted loading, the calculation is still simple; but it eventu-_ 
ally becomes more difficult, as soon as tune onm—uniform parts 
of the loading Come into Consideration. ine alm is more quick 
ly reached by tne graphical metnod. (See Zeits. f. Tietbau. 

1912. p. 237, 246). . : 

It one desires to make himself independent of the calculation 
of I and to deduce tne deflection from tne stresses, tnen with 
advantage tne following formulas deduced by Turley may be emp-— 
loyed. (See Figs. 60, 61, 02). 


: ly ioe : keaan 8. Ske Be 
&e Uniformly distributed 10aa; = me -_———— — 
Ph! 2016 (alt= x) 


141 


; = ree GO: 12 
0. Load concentrated at middle: 6 = -~——K-—-—-—— < 
2520 (an! = x) 
fer rahi, Ce Laie igh Gay 5 Age 1 
c. Cantilever uniformly loaded:. § = —-———&— fs 


| 840 (a! = x) 
Note Le PoidS5. AS an.example (FVa. 68), If x = 11 cm, 


200 x 11° 480 + 41.09 | ‘ 
Ay a ee on CO ee ee ee ee ~— = BS, 673 ow 
3 3 
I, = 2863 x 26% = 18,960 ow4 


& 
I = 88,873.+ 15 * 18,980 = 373,073 om4, 


Note 2. Pe 155. The formula is vased on the free support of 
the ends of the veow. If Fixed at both ends, multiply oy 1\5; 
Vf {vee at one end anly, Bubtiply vy 3\5. For deducing the 
formulas, see B & Bs 1908. ps 225. 

ior the deflection curve is here assumed the parabolic form 
of the elastic curve. 1 and (n! - x) are’ expressed in cm. But. 
the computed deflections are always greater than the actual 
ones, Since here also the tensile resistance of the concrete 
is not considered. + Yet if a Comparison is not found in favor 
of the ooserved deflections, then is to be presumed a defective 
execution. 

Mote 1. Po. 156, The formulas can also be employed, if ane 
wishes to take Vato account the tensile resistance of the cone 
crete. Then are changed the values (Cn? - x) and the stresses, 
end theresy also the Geflection a. | 

Purther see B & Be 1909, Be 294; 1910, p. 257, 1908, p. 398; 
1909, Pe. 22, AVIA, Pe VL, 1862, 225, 1912, 1p. 20. Bisenvertay 
1909, ps 430, 141. Runde. {. Tech. we Wirt. 11, No. Se Sobmeiz- 
DGUZe 1944, Vole 63, Ko. €0. ‘ 


* 
. 142 ae of rie oes . 
SECTION V. ACCIDENTS 10 BUILDINGS AND REBUILDING. eee 

At tne end of 1911 were introduced statistics of accidents 
by tne German Commission on Reinforced goncrete, and in Pruss- 
ia the Minister of Public Works gave to tne building officials 
lastructions by which thenceforth all accidents to structures 
oi reinforced concrete must be investigated by competent spec- 
ialists. ie 

A. Causes of tne Fall of Buildings. 

NOV] BePeidS. ALSO see the Vecture vy Professor Se NUVVer. / 3 
“BusVaing OffMaals and Pailures.” B & B. 1912. Appendix. AVEg . : 
see GContrvose 1912. pe Si. Arm. B. 1912. p. B14. : 

1. Statical Defects in Design. (Great numerical errors are 
selaom original causes). | | ae 

Detective consideration of the Snears, that by the occurrence 
of any defect in construction mostly nave an effect more unfa- 
vorable than the bending stresses. 

ASsuuption of actualiy non-existent fixing at tne supports. 

Brroneous assumption of loads ( for example, thicker slabs 
jogo assumed at FATES). Aueger ess esbimayion of the Bevable = 
live load. fater loading by ‘machines, not included in the Sta- 
tical loading of tne floor, or only later indicated wooden su- 
cerstructure on tne roof trusses. <S : 

Later recalculations and changes in the design, and during 
the ¢onstruction by tne architect or owner, which often have . 

a great influence on the statical calculation. Substantial ch~ 
anges in poSitions of beams, that are frequently not noticed 
in the local checking. Later reduction of deptns of beams, 2 
lostiy at the aesire of tne arcnitept.(Too numerous rods wita 
too little distance between tnem, fig. 64). | | | 

Note 1. Pe 157. Frequently Wn the Gesoriptron ore given irra- 
TVonar requirements Concerning the Beprn of beans. This Gepth 
Must always be in a certain proportion to the SPAne 

Ze Structural faults in Désign. 

ine neavier structural members are not oaly to be checked by 
Calculation, but also by a specialist. 

3- Faults in tne Construction of tne Building. 

Use of aefective building materials (loany, untested gravel 
Sana, etc.). Defective care in mixing and bamping, 6 displace- 
ucat of the reinforcement in concreting as in Fig. 05 (large 
StUrlps of tloors witnout reinforcement, etc.). Unpernittea sa- 


wee 
Bis 


Le 


145 : 
saving of cellent. NO attention pala to neat ana cola (see pe. 
i4i). Insuiiicient support of floors, foundations of walls ana 
supports, Unailowacle loading during ana after cons$ruction. 
Joe owner Later aoes not know tne load for which tne floors 
were calculated; y) overioading is at least possible, or a sua- 
aen increase ot concentrated live loaa. Qnanges in tne locati- 
AO of macaines on tioors (for example ot rotary presses in 
printing establisnments). Overloading of iloors with de 
removea centering. 

NOte@ 2. Po LD7T. Burt Lhe cowpressite resistance of the concr- 
ete VS Selaom exceeded, Much rather is reached the elastic Vi- 
WY Of the steel. (See Section VIL @). 

NOV] Seo Pe 157. One always has the advantage Wn vevnforced 
concrete, that the Gead werent Va so great, that an Vacrease . 
of the Vive Voud alane does not wake such a ereart aifference. 

oo weak Centering or too early removal (see p. 145, too 

apba removal or tne necessary struts (mostly at the desire of 
tne architect) or of the contractor). Althougn tne lower Stru- 
ts are removed, tne struts for tne upper floor are still set 

on toe lower rloor (see p. ido, Rote i, ana yp. 147; Rote 1). 2 

Unallowable reauctlons oi tne Compound structural mempers, 
just aS the Concreting 1S Commenced, or if tne concrete workers 
are alreaay gone (openings yor litt shafts, chases for conauc—— 
tors, skylignts, noles cut for heating apparatus, pipes for | 
@as, water and lignt conauits; see p. 145, aoe 

Dangerous effect of waterproot Coating applied too soon on 
the Iresn concrete ceiling 

Too nign test loadings. ye Ger l49). 

4. Detects of a General Kina. | 

imployment of uaskillea workmen + and of local foremen Wits - 
lasufflclént experience and knowledge. For permanent local su- : 
torintendent is necessary an experienced specialist (no impro- 
ver, ordalnary foreman or the like), for larger puilaings a pr- 
acticaliy experienced engineer. A general supervision by a me- 
rely occasional visit from tne office of tne conctractor is # 
not suirticient. “ 

Note 1. p.id5s. Lt does not alane suffice for the contractor 
VO Gssume sufficrent theoretical and practical knowledge of *. 
Wie new branch, efore al\ his assistants, his superintendent | 


GNA Vinprovers Wust oe wel) trained. In the country many wasons 


144 e 
esteem themselves sufficrtently competent to superintend as 3ke- 
VVVed {orewen the construction of reinforced concrete oui Varnes, 
the Supervision is just as ineufficient as the Lack of DUNVONAS 
off{rervals, Gnd evvV\ results Cannot Ror. An Lnoxperienced cone 
tractor Wit 2004 assistants can. eit eceg etter work than a & 
SPeGiaLhy Wained Gantractor with unexperienced Vavorers Onn 
Gorenen. The Swiss Regulatvons therefore justly require, HOG 
only 4pernissible fornmen Wust be cmp Voyed, who possess experi- 
enee HA tALS Ssusten of constructian.” 3 . 

According to the Dresden agreement for wages of Aug. 2, A910, 
a AVSTLAGTIOR 15 Wade between special workmen in Concrete can- 
structions -- | Cia : i 

Ge Butrorely skilled coment workers, \.e., workmen, who can 
prove at beast four years of work WITH Cement GHG NEtLTIBES, = 
and are able to work correctly frou &Brawings, to select the 
steel, bend in place and wire Vt, %o work and treat the concr-_ 
ete correctly and properly, to Lay off & Gerling Plane and sie ; 
TaVent and to Finish Vt, to construct a floor at pleasure with 
any SubdatoVsron by jgovnts, to further plaster and SWOOTH, ANG 
Vn Genera con work independently. . 

be Gementer and netting worker, 1ee-, workcen, that can exe- 
cute only a portion of the previously named work, and that can 
prove the practice of this actiorvty for ot Least ane your. 

Note 1. De 159. *The contractor ras to place for the Arirect 
supervisrvan of the reinforced concrete work AN engineer exper- 
Venced un this method of construction, during the construction. 
At the Gewanea of the builavas officials, the contractor is re- 
quired to prove, that the person entrusted with the CONGUGT & 
Qn superintendence in the erection 0G reinforced concrete work 
has already been employed successfully.” UNurtewbersd Redulati- 
OnSe Dec. 1912). -- If a specialist is placed in Local char he 
of the constructian, then the Nisher supervision Wust contain. 
the sane engineer, who had charge in the office of the calcule- 
Lions and arawings, who conducted the business with the of ficr- 
als, and who also made out the 014 and the estimate of cost. 
a\sO see the Essay, “Duty of License for Goncrete Korke” EB E Ee 
12146 De 16,5 1Site Gen sees 

ixtremely limited building eos: (pressure of owners for 
completion). 

xeauction of cost in Competition (saving in the wrong place). 


Riese é 145 
Disadvantage ‘of, ‘public competitions, in whica unacceptable con~ 
ctors can participate, frequently receiving the award by x 
Ps cheapest - bide age ky | . 

None or too late. checking of. the ‘statical calculations at ter 
letting the- conetract. : ; 

Lack of technically: skilled men in the building. office, who © 
have to check the building ‘project not only by calculations, 
but also structurally, and who know toe practice of reinforced — 
concrete construction by their own experience. « 

NOWe? 2e Po 159, Professor ‘ey wiVVer: recommends the cuca: 
USAT Of statical offices. Yhese require nts Nove already bve- 
en {ul{Wled Vm various places. In al\ cases the officials of 
the Leabnrical societres -- which was already considered -- were : 
wnaobe %O prevent bad constructions, these officials mostly x 
Vack the special knowledge. (B & B. 1218. .p.28, 200), 

5. Influence of Higher Powers. | Sor, 

Unavoidable accidents in which forces come in question, which 
are beyond calculation, tor example eartagquakes (p. i4), explo- 
sions (pe. 14), floods, broken dykes, fire (ped), digatning ate 
rokes (ps 109), etca, as well as acciaents during the work, w- 
unforeseen failing loads, movements of foundations by the sink- 
lng of tne grousa water, appearance of springs, vibrations and | 

ave like. : . Pe 
by the German Concrete Union was introduced in i910 an arbi- ~ 
tration aecision, that besides tne arrangewent of fees also @ 
Contains a list of competent persons,. By means of this list 
Suitable persons can be found at once in tae vicinity of the - 
acciacnt, who are capable of clearly estaolishing the Gause ot 
the acclacnt, and when engsagea, these are to make this public 
in tne shortest time. Tne appointment of sucn a board of arbi- 
trators 1s the more in place, that the abundance of zecnhnical 
guestions in court proceedings as well as tne nearing of expe- 
rts ls maae necessary, where it is to be considered, that by 
tac lengtna of time over which tne nearing of experts extends, 
eroots are made 

quite ditricult. It is beyona all 
aouct, that the establishment of this arrangement of a board . 
OL arbitration by tae German Concrete Union woulda have an ext- 


bhat tne 


7 ves (aa) ‘ | Y -* > 
rewely beneficial eifect, and nuleous court ices and mucn pre- 
C1ious time would be savea. 
be Formation of Cracks. 


’ 146 
Tne before mentioned causes of acciaents first allow tne fort 
gee ets eto 
* mation of cracks in tne members in sympathy. Naburally 


tne Live. cracks (cracks that €xtena farteer) are more. dangerous > 


than the dead cracks, that have come to reste - 

Note 1.49.160. Boery crack is nowise Gangerous. In this Tesp- 
ect One SHOULG not ve. SXCeSSively Anxious, and should Pabslaniiceset 
that under the sawe causes other structural, materials, Vike ag 
wood, Steel and wasonry in eeureetetek aK revaforced concrete. 
WVEW Vi Smooth upper surface, ali appearance of Wagurar and © 
cracks are recognized WE Wuch greater bees cea or not ot 
OL\e ; Re : 

Injuries to supports by cracks are extremely rare. 

injury by cracks in the slabs of ribdbea Tloors;: mostly enti- 
rely narmless sarinkage cracks (a) parallel to wae reinforcem- 
ent or sligat angle cracks (0). Only separating cracks fey may 
o€ Gangerous and Hake strengtnsning necessary. ae 

Injury by cracks in the ribs of ribbea floors. Vertical cra- 
CkS at about the wiadle of the beam are mostly uAimportant ten- 
Slon Cracks lin the concrete. Horizontal cracks correspond to 
the joints in the work and only make strengtnening necessary . 
when they extend deeply. Bntirely dangerous are only the obli- 

ge snear cracks in the vicinity of tne point of zero wonuens, 
tnat so Tar as they extena to the underside of the bean, are 
aiso visible on the bottom of tae deal. 

“Ge Rebuilding Works. 


in consequence of the strengta of ihe reinforced concrete t 


the number of such works is extremely small. Tney frequently _ 


reguire a preliminary reliet from tne loading by wooden scaii~ 
olds; tney likewise generally need extensive saoring. For the 
rollowing are given some examples of reconstruction work. + 


Note Lepetoi.e See the Lecture of Professor 8. ABVVer, “WRecon- ~ 


struction Works Wa Reinforces Goncrete™ Vn the Annual Assembly 
of the Gerwan Goncorerte Union in LQLA, Arw.e Be. 1914, 0. 1388, & 
L183, 820an 
7 a; around the old pier is tamped a new concrete ring. 
>/ b; reduction of distance between supports in toe Low- 
Story oy lnsertion of a new support (in stone, steel or re- 
orcea concrete). Disadvantages; new Benet moments without 
corresponding steel reinforcement. | 
1S. O/ G; lmsertion of steel beams below ana besiae tne old. 


} 


le! 


147 
Disaavantages; loss of neignt ana width; no correct statical 
effect; alfficult extension of tne beam to tne wall bearing. 
best are two side plave beams as in Fig. 67 a with cross conn~ 
ections through the concrete beam (less loss of neignt and wi- 
dine ? | ae | 
#ig. 07 e; bridging over these cracks by new rods covered 


w1tn concrete (bends placed close togetner). Good statical Gom— 


Clnation, especially when the side strengthening rods are con- 
nected together tarough toe beam. | 
Pig. 07 £3 box. enclosure according to Professor 8. Willer. 
Tne old beam -- after tnorougn wetting -— 1s enclosed by a new 

concrete Covering with continuous obligue ¢ enclosure of round 
steel rods. Two Noles extend beside eaoh-oeher serve to carry 
tae Steel up to the upper zone of tne beam. Toe concrete is 
toen applied in thin fluid form. Aavantase of this covering; 
ease of use, cheapness, executed in any tenerns, ees 
beam in a Gay’s work). , } 3 
Fig. 07 g; diagonal-lattice in the interior of the haat acc~ 
sige to Protessor 8. Miller, (or broad and neavy beams). In 
steaa of tae U-form Ghe strengthening rid has eit ~SLape. Tne 


wed lies in the-middle of the bean, the strengthening rods pass 


agaln tarougn holes, that are conically enlarged downwara; tne 
bottom of strengtnening flange is thus tootned iato tac upper 
OGalie 


Fig. 07 a; increased thickness of Slab, rougniag and soaking is 


Boe upper surface; then a new tamped layer at least 4 cm thick, | 


witn steel network (stirrup connections with the tension rods- 
of the old slab are preferable. i 


NOLS? LoPe162. On: svaivar SUV CRE ESE HR MEE works, also see .B & aa 


AQLA, Be BI6 ene | 

Hig. 07 i; mew connection of a separated wiser Shae. at tae 
compression zone of the beam (cracks ¢ in Fig. 66) 6: Cantilever 
rods in longitudinal erooves ecanected wita the lower  reinfor— 
cemente 


“a 


| 146 rat 
iy Structural Development of the Basal Horas, 
Ga of Sxternal Forces ana bending Homents. 
ppans of Floor Slabs. : 
St tween permanent loading, i.e. dead weigat 
, Suspended Rabitz ceiling, etce.} and live 
he traffic loading. “ With tne existence of 
d concentrated Wads, their most unfavorable 
introduced in the calculations. Some shock 
idered by corresponding additions to tne ex~ 
iRifornly distributed loads are to be assumed 
Ges according to the Prussian Regulations. 

iy Vive VOad Way also be understood the traf- 
ML Load (floor etc.). 

; a nenders Subject to moderate vibrations, £ 
floors of houses, business offices, ware- 
y existing dead and live loads. + 

morthy of conssdcration is the following 

a PBadkish Regulatvons;-- for columns or piers 
Maree or wore strong floors, the Voading in 
fies is %O Be ObVOLned as follows, for the 

Ws tO be Laken the full accidental boaa 
Pe yee oud assumed for Vt, for the floor 
wuost Vs Lo be token 10 O66. Less than thar 
oe. WMOSt, for the next 20 pec. Less, and so 
“story, where the reduction amounts to 50 Bebe 

: aba the stormy. For al\ Vower stories the ag- 
Ease Golumns Ve taken at 50 p.c. of the Voad 


es exposed to stronger shocks or vib- 
¢ y varied loading, as for example, floors 
@ancine halls, factories, storehouses; tas 
‘the live load increased to 50 p.c. 


rations 
ln asse 
actual ae 

Nowe @ 
the .@ : 
of wae 


Im Wanufactorics is to be taken Into account 
ment of heavy wachines. A Vater transposition 


By be GoNSevrous, and at Least way affora OoRnPr- 


TUnity Matvon Of too Large cracks. -- Otheruise the 
v Vor atte MALO Consideration for the slavs, Less so 
{or whe - or at al\ for the supports. ine 
, eetgies 
nana estrong snocks, tor example for celiar 
ors : anal Sand courts; tné actual dead weignt and the 
live logge 7 %o 100 De oe, 


9 zs 


= 
« 


oa 


‘ 14y 


mowbered, thar 100 p.c. addition for strongly 
Ae eee Taken ver Woh, nearly ALL ee 


alee Voad, out: ‘oO! reduction Pa: the steesses. 


Pisicias by <ee knowo unit data.” 
a on the values of floor loads are to ce & 
ble containea 1n phe Appenalxk. 4 Tae dead welenu 

3 be 0 be assumed at 2400 kil/m? according to s 
eee tac steel reinforcement, woen aS 
irected. Yet in wany cases, especially wo- 
° cement is eel developea, that ab must ae 


etween 2000 and 2300 kil/m?- (see ps 72)— 
omen (good as filling) wita a weignt or. 
3, as already sta ted, must fina use ing 2 
Biesetructis: only after preliminary tests. 


the PYUSSVaN Rinister of Pwovic Kovke OS foe 

Jan. BL, A910, wn reyerence vo the. oe 
iS to be sscuns for OUVALNES 6 (See whe ae 
mame). Accoraing to tais Gecree, Tor wind pice! 2 
238 | ¢ %) ane surface. Anclined @% to the arirection 

pre “We taken, K = p ein" a°. (Lass\"3s formula); — 

oe wos valia, OW = p sin a. ao) a ee eit 


Sesiad. yooft, S$ = 75 cos 0° ee of peice: 

wad. © Schaller (Loaaine of orchitectural st- 
TUCtM Brust, & Son, Berlin, shoulda ve useas-- 

7O¢ regions wp to 200 wm vvove sea Level. 

120, , 200 %o 500 m above sea Level. 

340. , 500 te 2000 Ww avove sea Lever. 

ah ae 
Accord: ; Regulations the dead weignt of tne 


Pa x es 
COnCrT Ste) 


at 2500 kil/u?, 1naeeéa with regard to 
the apie 


idable increase in thickness 1n conss- 


at. The weight of a unit volume of ‘tae os, 


’ 150 
construction.” wf 
For foundation slabs. and ait such concrete masses, where only 
a relatively small reinforcement and also (as a rule( no rich 


mixture occurs, a@ weigat ef 2300 kil/m? must be sufficient. _ 


But on tne otner hand reinforced ‘concrete of crushed granite 
and basalt way weigat up to 2600 kil/u>. 

As for tne lengtna of. beam in’ calculations, "so important ter 
obtaining the maximum bending moment, the Prussian Regulations 
state tac following: -- 

“for treely supported slabs, the depth of the slab at the m 


middle added to the free lengtn is to be taken as the distance | 
between centres of supports. For ‘beams of free span increased — 
by necessary lengtn of end bearings is to be taken as the dis- 


tance between supports. ” a 


Thus for a clear span of L in mis to be added. tne ‘thickness — 


d of the floor slab (Fig. 68), to be introduced as tae sSaiitern 


in tne calculations. 15 Ltd. Pea ee ail healt 


yorte 4. pe 164. For steel veooms as a. yule coleuvetions | are 
any wade with the clear span = “OVS Vance eetwcen SUPPOVES. » wwe 


reaulatron for TeInfFOrced Gancrete 2. Andeea %O | ae vegaraed.os 


H 


a et of safety. hs : ‘yo as i ee 
aturally it is not nere stated, “that tne pee, ‘a. of ‘pearing 


must equal naif tae thickness of tne floor slab. Toat would = 
suffice in but the rarest cases; but on the ovner hand, also 


sng requirement of a minimum length of bearing = 2h3 ec 
of tae wall, would often give ealues mucn too large, The depehiy 0 
a of tne floor slab amounts in simple buildings to 8 or. 10 oo ae | 


thus averaging 10 cm. . HN att ot a 
It is advantageous to determine wore ee Me ‘the. lengta 


a of bearing -- according to magnitude of the loading eo, 
whe cases, in order not to stress too neavily the masonry ben- 
cath. In tais case the requirement of a minimum length of Dear 


ing of 10 or 13 :Cm (nalf brick joint) suffices. 1 


Note Le Po 165. According to the Suiss ond the Austrian ieee 


Latvous, the Gistance, between supports, so far as not Gertermi- 
nea by the arrangement of the bearings, Vs ossumed equal to x 
the ovear sae Anoreaced BZoOur 5 PeGey Bee Austrr.an ReguLatio- 
ns Fix 10.60 as the Least Anorease. Regulations . BCCOrdiNs | +o 
which the Lengtn Vs %0 be Yaken vetween the @iades of the sup- 
ports, way easily afford opportunrty for woking the bearing as 


ie 451 


GS SwWALL.as .possrioLle. 


For continuous beams according to all regulations 1 = L.+b. 
is to be assumed . Yet particularly for small values of L but — 
great dimensions b of :piers, it must suffice to assume 1 = L 
+ b/@ for the length in calculations. (Fig. 69). 

be Slabs freely supported and those with ‘fixed loading. 

The rods, that nave to receive tensile and compressile: stres- 


ses are called the bearing rods of the structure. If a slab= 


pee 


rests free at all sides, these-rods are properly placed in the 


direction of the’ smaller span, For an approximately square plan 


is advisable a’crossed position of the ‘rods. * In simple build- 


ings-round rods of & to i5 mm are usually taken and placed ‘at © 
distances of & to 15 cm; distances below 8 om are’ not recommen- _ 


aed on account of difficulty in tamping. Bearing rods should — 
never be. spliced at points, . anere great bending moments occur. 
or great spans and loads the thickness of: boe slab is to be 


wade ‘quite great, or the steel: “reiforcement ‘is to be. made very | 


strong. Otherwise :oné always doeg well to: employ ‘rather ‘small 
distances ‘between rods and small rod: sections, than great ‘dis- 
tances and large sectiens. At the: ends” the rods are t to be bent 
as in Fig. 70. (Also see 'p.52.5- Furtner see. bakes 9 
NOLS? Be PoiSS. See. Section Vi- ee : 
In contrast: to. the bearing rods_ are. ‘one satan distribut- 
ing rods. These connect. the ‘former transversely and have tne 


purpose-of holding the: ‘bearing rods more secturely in. tamping, 


of distributing among those uniformly. the. effect of tne exter- 
nal -forces, ‘of ‘preventing shrinkage - cracks in tne direction of 
the steel reinformeement , and of increasing bhe ‘resistance to 
snear of the concrete mass. On account:of their suwailer “‘Lupor-— 
tance smaller sections are given to the distributing rods. than 
the bearing reds '(6 to 10 mm), and tney are laid over those, 

SO bHat’ tae: bearing ; ‘rods ‘may lie as near. as. possible. to. the & 
outermest, thus: the-most, strongly stressed Layer of fibres. | 
According to phe official ‘regulations, there must exist under 


tne bearing rods in the ‘beam at least 2 cm taickness:of ‘concre- 


te, or in slabs at least 1 em. Only for producing an increased 
security against fire (see p. 5), 1s a. geratar depth taken. = 
(2 to 4-cm). “4 

AL alternate. crossings both kinas of rods” are - bean togetner 
by wiring, so taat as a whole they ‘form a steel network. Tae | 


. 


b,/ 


452 

ends of such wires (0.7 to 1.0 mm diameter) after winding are 
twisted together with wire pliers. 

ert a floor slab be. treated as. a beam. on gy stovorta ac is 
waiformly. loaded, the arrangement of the reinforcement is 
mage according: to the ‘followiag ‘points of view; phe bending ‘mO- 
ments at the supports = 0; they ‘Lnerease -rebularly. toward. the 
middle, there. attaining | their: ‘Maximum value; in other: ‘words, 
tas -compressile’ stresses in: the ‘fibres. dying above. tne zero 
line as well as the tensile’ stresses in. the lower gone; of the 
slab-always imerease toward the. ‘middle (ot span). : 

Fig. 71 saows tae simplestf: ‘form of a reinforced concrete @ _ 
slab. The reinforcement ‘is only placed - ‘in the tension zone, # 
wheretore all compressile stresses must be received | by the dake 
crete. It-is naturally advantageous to. ‘place the Steel rods as 
near as ‘possible to the ‘most. strongly stressed. external ‘fibres, 


to increase the ‘useful effect. fo save steel, one may ‘proceed 


according to bae arrangement bo, taus making | the second ‘Or ‘third 
rods shorter. -- If one desires to save- ‘concrete, ‘its: basal ee aM 


form~in-Fig. 72 is chosen. The steel -rods here» not. only kevin.) 


the tension zone, but tney aiso aid. the ‘concrete ‘in. receiving © 


the*compressile'stresses. Yet the effect: ‘of the steel : -reinfor- 


cement in tne: ‘Compression. zone ‘is. quite. unimportant, “in compar- 
ison to its effectivemess-in the. tension. (Zone, - -as will ibe: lat- 
er proved by claculations. + The dimensions and: arrangement of 
the compression reinforcement naturally does not ‘require. to -# 


correspond to.the tension. reinforcement, as. Fig. 092: Shows | in : 
' both sections. -- It is: ‘advantageous: as. a reinforcement as-in 


Fig. 73, indeed ‘in. regard to. the fact, that: ‘On the one band - hes 

the tension rods are 20 longer. ‘necessary at the support, bay 

on the ‘other that ‘with tne Seas: degree. of fixing negative: BO- 

ments wag Occur. . 
NOLC As Pe 16%. ‘See Section 1x. | 
Nove-1. Pel68. Pixing - ‘Cesubts from the mone perfect counect-_ 

van of . the Floor and wabl, and from the arched hduhoae. Of the 

angle. (See .B & Be 1908. pe 295). * 
fhe utilization.of the structural materials (especially. foe 


rloors of greater spans) is more effecient, when the slabs are 
so-fermed as to become ‘fixed at both ends. First of. ay: bre 


deflection ‘is' then less than with -free : ‘Supports at the ends. 
tne elastic curve shows two points of ‘Change .of ‘curvature, SO. 


that the bending moment at the two ipoints. attains: tae Z28ro 


i” eee 
value. Tnerefore ane ‘has :positive and negative moments, the m 
haximum value of tae former lying at the middle, while the ne- 
£atlve are maximum at the fixed ends. Accordingly in the middie 
part of the slab the lower ‘fibres are in tension and the upper 
are in compression; conversely at the fixed ends the tensile 
Stresses lic in the upper zone and the Compressile stresses in 
‘the lower. According to Fig. 75:-- } 
al aye 
+ Mionax = Ry “= Muay i a e x i - about = 5 oe 
But these values require a uniformly. distributed loading and 
re only valid when tne cross section of tne slab remains» anc- 
hanged, “ and also the: ‘bearing ‘rods suffer no alteration én ¢ 
dimensions and:position. Bat Since botn these are excluded ‘in 
most cases, the given values-are only an approximation. To save 
tne statical proof of an existing: baie: one gap dimension + 
the slab for a maximum moment M = f--- to + eis taking ‘ia- 
to account the occurrence | of ‘negative "fixing moments by arran- 
ging arches and -by | carrying the reinforcement at ends: as ‘Close 
‘as possible: to upper edge of slab. : ve 
Note 2.pei168. See “On the PLxed Bean with Variable Moment of 
‘Lnertiac® Arm. .B. 1908, p. 171. -- But experiments of the Ger- 
won Gowwission (ieft-18) furnish evidence, thot beans fixed at 


woth ends., a8 wer as beans fixed at one end and freely supp- 
orted at the other (PIG. 78) may very well be. Colculated accor- 
Bing to the usual wmode of coblculating. “ROWOSeneous » @Vastic - beans. 

It is mostly advisable to reject a complete. fixing: of the = 
slab, since in many ‘cases the necessary conditions are wanting. 
indeed the fixing produces a substantial economy in materials, 
and an ‘important stiffness. of the whole, yet in external walls, 
so far as not themselves. constructed of concrete, ee a Ten Stee | 
ing is made with difficulty.’ ‘i 

WOtG 1, Py, i168. For exawple, no perfect fixing Can be asserted, 
‘VI the stood Vs only Vater iaserted into a recess. Also see He 
“PLxed Floors and Beaws of Reinforced Gancrete,® Z& Be 14908. 
‘Pe 116, 2415, 1909. gp. 290, B61. -- Burt experiments of Buperger 
with fixed beans (Report of Austrian E.BsA. 1213) nave shown, 
that beans betucen walls must always be reinforced for a .part- 
Vol fixing, -cvoen Vf .ecarcely Loaded at the supports, thus bei- 
BE UL BVIGRELY WUILt in. 

It floors are tamped between I[~beams and rest solidly on the 
flanges at botn sides, then according tO ministerial decree, 


ih Q1 
they may be calculated only by tne formula, M = + --- . But-in 
tae case, where the junction.is.arcned beneatn, sat the reinf- 
ercement iS anchored fast in the adjacent panels, doubtless a 
nigher degree of fixing may be used in tne calculations. < 

Note 2. p.i6%,. Floor slabs betucen I-beanms must inno case 
ve calculated .as continuous beams, according to-the Prussian . 
Regulations. This caleulatian is only albowabhe, Vf the slabs 
rest on reinforced. Concrete Reans. ‘For reinforced : ‘Concrete coan- 
Struction im generar wisi. this regulation ve regarded .as : Rovor- 
aoe, VW adinectlhy Rosie s a ereater: use of unifora. orrangenent | 
of T-veans. . 

Sbabvs . binge ta ck betNeen - UG ad ‘in Pig. 74, may be flalc- 
ulated With ---., and only With ---, if greater heigat of beam 
(n = or more than-4 d).and the usual distances exist between 
pte pports. 

If one is in. position to. obtain the points. of change OL. tne 
elastic’ line, thus to establisa.ahere ‘in the» upper zone tensile 
stresses cease and the .compressile: stresses - ‘begin, then. may the 
basal form be employed, as in Fig. 75 a. Only a Single: steel 
rod 1s arranged, ‘but ‘wails. ‘ie consequence ‘of its bending to .cor- 
respond to the. elastic: line suificiently resists» botn tae ten-— 
sile stresses in the upper zone as well. as those ‘in the lower cs 
zone. ‘The arched ends afford @ better fixinga. + It for compi-_ 
ete fixing ao arches are arranged, then on account of the. ‘great 
fixing moment 1s required very strong steel reinforcement at 
tae L1xing points, but which must extend still beyond the. poi- 
nts.of zero moments. (Big. 75 b). -- If no perfect fixing exi- 
stsybut only a partial ‘fixing, then according to the degree ‘of ¢ 
fixing (Pig. 75) -- only a portion of the reinforcement is. car- 
ried upward. According to Pigs. 76 left, eaca fourth rod. extends 
» Auto the tension zone, in Fig. 76 right, each third rod. ‘Besi- 
 Sbs. according to Fig. 76 rigat, above all continuous tension 
rods a are also placed special ‘reds c in the upper ‘gone. The 
basal form in Fig. 76 is representative of most floor constr-.— 
uctions in reinforced conerete. + For the arrangement of the 
reéintorcement is always determinative ‘ak tae form of the ‘moment 
area, above all the rods must not be bent too soon (Fig. 73), 
the proper reinforcement being dotted. -- According to Fig. 

77 whe rods ¢ are carried through from one ‘fixed end to tae 
other. . , 
Note 1. .O. 170. Every arched end Increases. the cross section 


y™ 
. 


455 
at the f\xea end. The effective depth Ww - 0 vecomes greater, 
SO that a a Siven case, Vn spite of the cabcuLatedeveater. 
MELAtLVE Moment for fixing, there can suffice the reinforsenanrt 
For the positive maximum moment (at the middie of the slab). 
ASee Section WILT). 

Note LePelTi. For very thin fixed slaos, nowever for practi- 
COL NEGSORNS, “UPUGFG Hends ove Less usual. Herve orvangeucats + 
Vike Pig. 75 0 are pregerabte, i 

Big. 78 snows a beam wita one:end fixed and the other: eeoeiy 
Supported. Tee forms ‘of tre Peintorcement here correspond ie) ) 
the occurrence of tensile stresses in the lower zone at tae 
supported end, and inp the upper zone ‘at the fixed end. 

‘With structural members projecting as - ‘consoles, - ‘Slabs ‘are. io 
be regarded as fixed at one. Side. ‘The stresses in the building 
materials are opposed to those iu Simple beans. on two. supports; 
the upper fibres are in tension and tae lower ‘in Compression, 
for which-reason the upper half of the ‘cross. section*is to- be 
strengthened by steel reinforcement, as shown : in Fig. 79. -— 
It tae projection is quite. ‘unimportant in. comparison. to. the =. 
cross section -of tne slab, then it is. advisable. also. to place 
steel rods in tke compression - ZOne. ) 

‘Rig. 80 shows :a freely: supported. beam with. an overnanging © 
end. (Compare this with:Fig. 78). An arched arrangement as ‘in. 
Fig. 30 b permits a reduction of tne tensile. reisforcement abil,” 
BAS point of negative: moment. of the ‘Support. iar | eters 
n= a). 

On steps of artigéicial stone with «fixed end see Part GRO a 
th edition, :p. 65, (Decree sof sBorhan Buliding ‘Offiee. “Garon 
i9, 1913). : ; | Ne ; 

Concerning the mininan thickness of slabs, the. Prussian ‘Reg- 
ulations prescrive. tne following; -- 

$Tne calculated thickness of slabs: ‘and of- slabefarued: parts 
of T-beams ‘is evergwhere to be made at least S-cm.” 

Por phe work of many ‘inexperienced -conctractors ‘may this new 
rule be of a-certain use; ‘for any even small deviation of the 
steel -reds from. their calculated. ‘height may have the. most ‘inju- 
rious effect on the general construction, particularly if occ- 
asional saccks are not to be avoided. Yet in many cases .both . 
raw materials are not utilized with sufficient economy. For . - 
slabs for reinforced concrete roofs ana hall buildings.a pwat- 


156 
sualler thickness (to 6 cm) is still permissible. For. ashlar 
and hollow block floors in tne form ot T-beams with tae small- 
est possible subdivision by ribs (30 to 50 cm), as well‘as for 
suspended ‘plastered ceilings, the regulation does not come in 
question; also see Section XIV..(Decree of Nov. 22, 1913). 

Floor slabs in simplebuildings are not ‘generally made taick- 
er thaw about 12 to 44 cm; otherwise is advisable ratner tac 

ed:ot ribbed floors (f-beams). For cantilever floors, one may 

p ” to 20 cm in thickness; ‘but otnerwise :here also mostly T-be- 
ams are more economical. - ‘Only. for the driveway . floors of. brid- 
ges does one go to the taickness of :30 and.35 cm. ‘Qne must. al ~ 
ways consider, that the dead weight increases: ‘in an important: 
degree with. the increasing depta of the slab. ie 

Mote 1. pel%3. A veduction of the dead Load is obtained. ney: : 
the use of hollow vlocks - Leese Sesrtian SIT) or of putes: cons 
crete floors (see ip. 45). : 

Notable 18 also the requirement of the hue eis Regulations, 
according to which slabs with less than 6 cm least thickness — 
‘Cannot be assumed in calculations as cooperating incase of 
T+beams. 

‘Also seein’ Section WaT “a tae-rowaing test given for a rein- 
forcea concrete ‘floor only 4.5 cm thick. 

GC. Slabs reinferced Crosswise. 

‘Rooms -of -rectangular : and approximately: PAD eae ‘may advaa- 
tageously be covered by slabs. reinforced “Crosswise, which are 
freely supported at’ ail: sides, | are nakt or completely fixed. 

Pac assumption of support at. all sides affords a certain. econ- | 
omical advantage, since: here the: ‘otherwise usual distributing 
rods aid in tae: supporting effect. ne. advantage ‘of less conc. 
rete is indeed: opposed. to the disadvantage of the. Sreater: use - 
of steel. 

The Prassian ‘Regulatioas prescribe tne following: -- | 

“Slabs supported at. all. edges” and furnished wita crossed re- 
inforsement, for a uniformly distributed loading, if. their len- 
gth a be less taan 1 1/@ times their breadth ’b, may be caleul- 
ated'by the formula-M = rel Against the negative fixing mom- 


ents-of désieensureelaken to: be provided arrangements by tne 
torm and position of the steel rods. ” 


a“ 


Here also-is considered but one dimension of tne slab (the 
soortefst side); ‘bota for the square as well as for the. recta~ 


ke tne 


pl 


157 

rectangular slab -- with equal lengtn of tne side -- tne same 
value is used, and the cross section found for the steel is m 
then to be placed lengtnwise and ‘crosswise the slab. This. off- bike 
iGial rule presents few advantages: ‘in all cases the cost of. 
such slabs under some conditions would be higher than :for. sin- 
ply reinforced slabs. One would do better to arrange ‘intermed- 
late Pibs, » ‘producing | ‘hess taickness of slab aad more favorable ie i 
it sausis tien of tne loading. The ‘tecanical dadvantage of a cr a as 
ossed reinforcement, “Qbtaining : a more uniforn transmission of : 7 
forces, and the ‘aid of the Gistribating ‘rods in. the statical — 
cooperation, is however lost. : s 

fae difficulty in tae calculation ons crosswise reinforcement: 
of slabs ties. first in the indeterminani : ‘Terces at tne Supports 
in reference to. magnitude and distribution. along tae. ‘edges. For 
example, for a corridor floor of slabs. may rest Treely on tae 
walls, but are firbly fixed at the beams (Fig. 81). in vais: o 
case must one ‘certainly take into. account the ‘fact, that. in % 
tne direction of the walls the slabs are. ‘substantially. stiffer 
than in the otner direction, in consequence ‘of tais. fixing. 1 

Note 1. PelT4o. B& Be. 1944, =p. 243, 302 Kostn. 0 comparison . 
of avfferent official regulations). _ Man, SANS Bae | 

Tae effect of crossed reinforcement is so. much the: (eredtar. 
toe more nearly tae plan of the room. ‘approximates the square. 
lt will: also be advisable, to-make the middle ot the slab. esp- ‘ 
éclally strong, sisace there the stress reacnes the. ‘maximum -val— 
ue. If in Fig. 82 L be tne longer and 1 the saorter side. ‘ot the 
rectangular room, then one employs with a uniformly. distributed 
load tae following relations. for. calculating tne = ernest ag: mome~ ee 
nts at the widdle of the slab:-- , RS OE dae iy 
QL a ir Bebe ee ore pas 


"ber eae he i ies 


NOt] 2ZcporVhe Derived from. the .cauation aes Act Laction ; Of 
Slavs with {ixed edges and. ‘UNnbTormly AdvetriVouted Voading. 


GX xMx HX xBQX, , ph Lt 
Pe) = hm x agian = fy x ae: 
By i : Ep Er 


Here is assumed .a free. aNEESTS) at all sides. If a certain # 


fixing, moment is bo ne\aousidaped, then one introduces the forsg 


QL , Qk aL Ql ere hae 
ul wees ce > ——em =f | nme nee oe: - j ‘ i a x! | a 
nulas ig” aad sa= , or ip and +5 tego REAR | be pre 3 Fixing) 


aye 158 
PIT? 
‘ita complete fixing as in Fig. 88 (strongly arched ‘junction 
and continuous slab) is to Bena oo iB the formula: -- 
4 


For middis of siao and 34° 
QL ; Ql 
tA ; ea oe ad ——~ ~——— , 
At the support ow 73 an 73 


. ri al 

for a freely supported square slap, L = te SRG oes 1 

Note 1. Pe 17d. ACcOVaGing to the ' Auvestbgations . Pay, POpPL the 
wowent for the freeby. Supported. SQuare sab \s- Me fone. TROY 


24 

PVATLCAL Purposes Gan be taken ‘Ae. average oduens M eal 
aps for sbstehe had Tvxrvngd, My, = 4) =" ar: dienes avaadle ot the. bisbty | 
ond i, = Bay at the eage.. es 
According to. the views of Professor Mbrsch , for square slaps” 
uniformly reinfor¢ét in two directions, one proceeds. MORE aafe- 
ly, if for tne positive. and asgative bending | women ts - are. eacn oe 
taken one nalf thesef& whica. result for a continuous: ‘Dea exten 
dgeadein one direction. ! ee | 

In tag following Table are collected tae tealues: of sary 


i te 3 
and Lan 14 for the wost ‘Common | proportions | of. ‘Ooms. — ae Diner, . 
Crosswiss reinforcement exerts. no: effect worta mention, as. oa 
as Lb = 1.5 1. From this— Limiting value onward. the double. sided 


support is to be neglected, and. the mowent optained | in Tefere- ie 
ace to Lo, | | 


: 8 
; air Vig isa ae hg ei. 
b 6 LO EE aT Se Ta 
P /¥6 i pea Tee | a ae 
d= » 0.800) 0.508% ) 0.678. Favede Yo sogs.* : alees 
5 = 0.600 0.408)) 04826 00-260 0.2027") 0 5166. 
Por example if L = 5.0 w, 1 = 4 w, g = GOO kil/m*, then by 


s use Of the preceding Table results tne following calculation. 
: = 1.26: a = 0.710: 8 = 0:290 (oy interpolation) . 


Mr = bald 89 x 100 x 0.290 = 54,3875 com kil. 
2 
i) = a ke x 100 x 0.710 = 85,200. cm ese 


The moment My about tae shorter side detemmines the thickness 
of tne slab. The reinforcement itself will pe placed closer » 
next tae-madale of tae slab for practical reasons, than at the 
edges (Wig. 84). 

Jn the basis of experiwents made by Bach (also see BR a 
1v0¥, p. 3886: 1910, p. 130). and which nave shown that the wex— 


159 ee 
waxiwum pending moment must occur in the direction of the diag Rs 
onals, taat 1t is also verily probable that the diagonal section ~~ 
‘is the dangerous Cross: section, — tae formula was obtained: 


Bh. 07 pe de L? 


(eae a 
It is here assumed that the loading is. uniformly. distriputed — Ce am 
on all four sides, one fourth to each. i 


“kote Beds L786 feeeocdage token. Menewon, isbe apesneee ON bowie at 


ae of the aides. One is even: guatitrea. yn the mem, | 
‘hat with a continued increase inthe Vooding the svao- AU a 


rise frow the supports at the. four conners. | Beas. 


Mone Swiss Regulations. (Likewise the. Wurtemberg Rouniatiens - Lt hy GAR ae 
assume tae total force equal to the. suu of tne supporting fom a 


ces of two separate simply reinforced slaos, and recommend the — 


distripution of tae Loading. according to tae following relations. ee aN Dae 
A *o>* ig ie ea No ait Poe 


Portion of loading = 4 Pp for. ‘the: span Lae 


‘Ly 1? ate Lo 
Portion of loading ; Piy = ire iF Pp for the span i 


It is here assumed,. that tne. supporting. forag depends on Te~ 
aching tae: elastic. Limit,in the steel. reinforcement. — ae 


The: Austrian Regulations. prescribe the: seplirintertecieoen 
Pale R oe os 
Portion of loading» Pp) = wera p tor the. span ‘deg’ 


Portia nee" te ates eier El b ry for. the. span be 


ere k denotes the ratio of the sectional area of the. series Chae Mane 
of reinforcewents parallel . to L to. the sectional area: of ‘the = CO eta 
series of reinforcements. paraléel OA ibe th ‘sectional : areas . 
referred to one lineal m. Gorresponding to this distrioution 
of the Loading are. to be: ‘abtained | the shears, loads: on supports — 
and ‘pending - momen tS. ‘The galculation’ only bas- to be made. for Rape 
the Least side, as soon as the sectional area of one series of 
reinforcements amounts to ‘le&s than 30 p.c. of tne sectional 
area of the other series of reinforceuents. For continuous sl« 
aos one must proceed properly according to the mode of calcul 
ation. i For all pan tanner ite Sane slabs, however, aes ‘positive 
nOwen ts vgeuhsinasea> ca beast’ Peet slap of a sinpve.puneaid 
Kote 1sp.i%. Besides, the Viteratune concerning crosswise ia 


Rac + it 


‘160 
reinforced slavs, veference ts wade to the following publicat— 
‘Vous, -- ; 

Bosch, Galouvlatrvon of crosswise reinforced concrete slaves, 
Wa. Beast & Son. Borin. Donusso, Lecture an caloulation of «a. 
crosswise -veiAforced concrete slabs. Wa. Brust & Son, Berlin. 

B & Be 1905. -peaTl, AVAC, -p. 130, 355: ASL, p.243, 1913, pe8t, 

Contra, 12900. 9.62, 67, Fh, 92; 1942, peo, 162, AWA. -Calour- 

ation of beams under crosswise» ee ae svabs,” « & & Be 1910. 

Os Bag FRR | | 
a. Continuous Slaps and. Beams . 

Fixed and continueus slaps and beams - ‘play supstantially a. < 
greater part in reinforceti concrete construction than in pure | 
steel construction, ‘where the fixed ends. are ) ab WRES Less. B0,°* 
assuming similar conditions. ayy 

; € Prussian Regulations . oniasutae: che following: ae On 
A - slaos .and . ‘beaMs, that continue over several panels; sin 
case the actually . occurring. momen ts and -reactions at tae: Ssup- . 
ports Cannot be calculated according ito. the rules in force for i, 
con tinuous | beams under the assumption Of free support On the a 
widdle. and: end supports, or cannot pe. proved | by experiment, 
tne bending mowent at the middle. of the panel | aust ‘be. taken oie 
4/5 ine value, that would exist for a slao freely ‘resting on A, 
two supports. Above tae supports is then to ‘be assumed tae neg 
ative pending moment as large as_ tae bending moment ‘in the pa- 
nels on both sides with both ends freely supported ."According 
to this rule, slabs and beams can only be taken as. seeder 
if tacy everywhere rest on firm supports lying in a plane. Or 
on reinforced conerete girders. In tne arrangement of tae vein 
forcement in all cases particular care wust be taken for the »\. 4 
possipility of the occurrence ‘of negative moments. . a 

for beaws a fixing moment at the ends can only be assumed 
and euployed in calculation, when particular structural arr- 
angements afford an assured fixing. ; 

Tae assumption of continuity for calculation must not dxkesa 
over more than taree panels. For live loads of more than 1000 
kil/m?, tae calculation is also to be made for the most unfay- 
oradle distribution of the load. noi 

Note L.epoi7S. "Burt according to. the decree of April 14, 1908, 
the caloulatven for Vine Vood unrforuly aietributed over the 
Separate paneLs tS NOL Bade generally, and abso Vs not permis- 


—_ = 3 : e 


netic 


161 
perwissivbe for loads Less than 1000 kibla4, otherwise sane 
BLEKT par ticubarby place the woment at widdle of pane eo oP 
for p Less than 1000 wAV\ a4 "y Corresponding to the. actual 
worarns of ene) Preceaimse Regubytion. But On unequal. avetribut- 
van of whe ,Vouding WUSH Wore ‘Corresponds » to. the: actual conait- Lhe %, , ee 
Vans Va awellings and : vuseness wurivaings | than a. wntfors atetr- 
/Voutron. aby ieee 
On tae basis. Of .. these requirements, (assuming adaberuly: dist- 
riputed Loads gg and p and. uniform Spans l, the method of cali 
lation given on page 179 is. possible. i 
As supports of :continuous slaps or beams, may serve:—~ L 
a. Walis or supports. of conerete or of. ‘wasomry. ry 
0. girders of reinforced concrete. ‘(T+oeau. ribs), or ‘T-beaus. 


lonents: ‘ : eee LOX. See lBt'2 EMeafettsagrte; 


rr el 
pan. Pan. «moment + 28. a ye ppl? LG by t 
sup. Sup. woment — 125. ht ae = eg + ?) LF, 
3 or more i ea 


ii. 


P19 


C Ww 


pan «endspan.M. + O.tle + p)ae a (08. ¢ x wie pie . 
4or widspansd .+ Q.i(ep)l® + (.02b.g © 107%) plat” 
wore soa and + (:.025_ ge 05 p)l? . 
supp. sup.momeM 73125 (g tp)l? —- (.10 g-+ Bote pit. 


(See Taple in iogiaae 

for tne walls or supports. for the same girder are. conplayed 
as far as possibletac same. bpsilding materials. and. Similar. fou- 
hndations (indbocl caneugans Gayekacoriia) cracks in a continuous 
girder are very often to be referred to the fact, that partly a 
free support on masonry, and partly fixing to slender and-elas— 
bic reinforced concrete supports are employed. Particularly. t 
toe middle supports sooner show 4 tendency to sink, than the 
external walls. — | . 

Slaps on réinforced sugauasal rips (T-bean floors), according 
to previous experience may unnéesliatingly be calculated .as con- 
tinuous peaus over supports of equal helgnts, so far as the £ 
free lengtas of tne ‘ribs ape ‘kept within the usual Limits. The 
deflection of the rips is only small, particularly if these ode 
again arranged as continuous. Likewise a very stiff connection 
octween slab and rib exists. For greater spans:of beams is ad-= 
Vantageous the arrangement of load distributing cross beams, 
baat permit no great differences ii the elastic deflection of 


162 
of the aajacent beams. On the contrary, if the ribs consist of 
I-peaus, tnen must primarily a greater deflection of the beams 
pe counted on, that-resulits in an unequal nelgoat of the SUppO- 
rts of the slab. Besides, the connection petween tae I-beams. and 
slabs cannot be as free from onjections as with reinforced. con- 
(erate beams. On these grounds itis generally improper to eal- 

culate slabs resting on I-bdeais according to. tae | rules for con- 
tinuous siads or peamsh | One 1s here, satisfied, . according to £ 

he construction, witn aodout M = —-- for the middle. and about | 
== for the end panels, as well as a suifiéie nt- reinforcement — 
at tae Locations of the negative woments at toe supports. For 
unequal panels negative moments may also come ‘into considerat- 
ion. (See p. 182, under 5). + a. i | 

Note 1.0-180. Further see B & E “AQ43.. /hS5. 


Also se@e the Regulations of tae iprodiany iat the Bailding oe en 


fice of Berlin concermans ground. principles rot the. calculation 
and construction of reinforced concrete. ‘J-peau floors, Decree 

fF Nov. 22, 1913. (Section -XIV- of this volume) . a | Pe 

a calaglating continuous slaps and peams in. reinforced : con= 
crete construction, tae following shoulda be not ei 

1. As for approximate calculations, tnen “= produces # 
very deep sections for the widdle panel, but st eaty. accurate 
ones for tae end panels. fhe use of the Tables for the waximun | 
nowents (see Appendix). affords suostantial economy in) materials. 
Otnerwise ior approximate calculations ine following values Brey) 
to bs recommended, <pbut onky for small Spans of slaps and sual 
live loads. (See Fig. 85 for tais). BS | | 

i, (over interuediate supports). =>-",,out Soe for - tapes 
spans. (for simple floor slabs, on account of the arched conn- 
ection ana tne bending of tae steel, one can generally omit a 
special calculation. of the Moment — M, of the support: also @ 
see Pig. 163.). | iat 

,, (in the intermediate: panels) = + =-- to --- . 


Mm, (in the end panels). =\+ =~- to -=- . 


3. lt would be advisable to extend tne calculated assumption 
of continuity over more than. three. panels: for the moments . Mg 
and ii of tne widdle panel become so mucn tae freater, the more — 
panels that exist. Only for the determination of the sections 
of tae end spans suffices tas assumption .of continuity for. th- 
rée spans. : 


“aly 
Gi 


163 
tnree spans. The maximum values for moments and shears are fo- 
und for partlal-toading, according to Fig. 86. “ 

Kote Lepe1B1. 4\V30 See Boerner, Statvear be iad: tn hati 
yp. 101. 

3. If tne Live vena assumed to tre uni fornly! distrivatea 
ever the entire beam, for example as usual :for roofs With uni-~ 
formly distributed snow Load, then the moments of ‘the widale 
panels would be too small: ‘for exam ters cope pup, supports, tae 
moneni-in the middle. panel is only Me ees . Already ‘on. 
practical ushered ae pote not go below tne value. for tale 
plets fixing, M = —----=--—- ; for to the saving in aetakl sae) 
is Opposed a reduction of the factor of safety. 6 7 

Note 2epeiSi. Tt way. Occur in test Voodtngs, that by ugaaee! 
ankby ao strip of the widdle panel (thus without. Voading the ene - 
panels), the allowable stress im the cancrete at the Centre) 


WILY exceed wore: than: ‘TPivejorvs, Ond- that the. tensive stress | An ity 
the steci veaches. the veusiie resistance, BOON" VE mot quite 
SXCCOGINE LHe -- 1% 18 also further proposed, to only fully — 

Loo the panel to ve. tested, assuming the ioswer. ‘paneva as. omy ren 


See B & Be LVL. H.38. | aa 

4. If greater live loads are to: be paiken thea even with, a 
division in.equal panels a continuous upper reinforcement is. 
higge recommended. ‘For smaller. panels under sone conditions, — 
a greater thickness of slap is necessary. (Fig. 87). ‘From p = mee 
800 kil/u® is abvisable-an exact investigation of the. existence — 
of negative panel moments. But to be considered - tas. also. the a 
frequently important reduction of the panel moments. by resist-— 
ance to rotatdon of ths strong, rigidiy enclosed reinforced ec 
concrete girders. (Fig. 93). | 

5. Negative: panél nomen ts (great live. loads, unegual | care 
ubion on the panel) are especially to be considered for. beams. — 
According to Pig. 89 must even be assumed a greater depta of 
Oca in the middle panel, since otherwise ‘it would lack tne 
required compression section (below). In extreme cases, to re- 
auce tne depth .of the ocam one may extend the width of beam for; 
tne middle panel or the width of support as iu Pig. 89 Db. One “ 
tach rather kas to do. with a. portal beam : (stiff frame) . To pe 
considered is, phat: by .tne sbift arcned connection. of the uid- 
dle panel beam with the support the negative nowent is materi- 


qa 


4 


164 

waterially reduced. The mathematical proof is lLaporious, put 
“(, way afford considerable saving 1n cost. The supports are & 
then also to be investigated for bending. “ (see Pigs. 90 s9%).. 

NOte Le Do 183, Tae bendias wmoneat, “wWHLGH the beam: Un conseq- 
wence of VIS T1Sia connection: WITH: tne. eee ys exerts. On shat, 
VS SO Wuch the greater, she Varger the moment of. ‘ertia: of * 
the seotian of the pier: VS Un. ‘CoMpurison to. that of. ‘she section 
Of ae ‘ceam. ‘For slender (for .exanple spiratly banded) coluans 
ny COVCULATLON Vs More necessary that for thick columns. (gee 
omong others B & B, 1912. pe. 271, Further, Schevat-Pravet, MIn- 
VSStVZatrvons on Bahu aig itera eedahhat: 'GOnorrte. structures,” Bor- 
biwe 1942, (Boa. Be 122. Pe 194). 

6. Toe sovcalled Winkler's nuwbers | given ‘lin the Appendix ‘for 
tae calculation of continuous ‘slabs : assume ‘freely’ ‘wovabee - ‘poin~ 
ted supports, but’ which indeed never exist in practice. Ta con- 
sequence of the Pixiag. at the ribs or supports, the reciprocal 
influence :of the adjoining panels is. less: also the: elraers: ¢ 


Oppose a great resistance to. rotation. ‘For beams» with wore than 


five supports tne middle panel | ke ‘pe approximately calculated 
as the second panel, and the end. ‘panel. as tae first panel of 
tas peam on five supports. Thus: ‘one restricts. hiuself. not too 
strongiy to. the women t areas, and for example, ‘he always. -asau- 
ués & Continuous tensile - reinforcement, even at the supports, 
woere it is properly not: necessary. =— The’ Tables. properly - re- 


quire a beam construction with. constant cavss section’ and leo 
stant moment:of inertia, which ‘however ‘is excluded. ‘in: consequ-_ 


ence of the varying position and sige of the reinforcement in 
reinforced concrete. The Tables are also only valid for equal 
or put slightly varying spans. If greater differences in spans 
exist, then the cakeulation is best made by the ala-of. tac. /eq= 
uation of taree woments -(Clapeyron's equation) © or by. the. re 
VF ty ins wethod according to. Ritter. 3 ‘By tac use of supports 
cae Is dependent-.on:taeir. building uaterials, bul. especially 
on the reliability of the foundations and of the grouna at the 
oullding. Por ‘example, in a certain case (p 3 600, g =-700 kil 
/u lineal), according to Fig. 92 for a difference in height of 
vac supports of only 2 cm, the shears increase avout 55 \DIGe, 
and the Moments even 165 pc. A sinking of the Support always 
reauces tae moment at the support, until it becomes zero and 
finally 13 even positive. The beam then generally rests on it. 


gues 


165 
no longer. On the contrary tne panel moment increases with the 
increased sinking. 

Note 2. PpoeiB3. Bhe Gonsiructor stares, that by the use of Cl- 
APSYVOR’?S fYormuba the POSiTVoe - panel wonents are sonewhat s00g 
Large, but NELATVOE » MOMSRES | Ot. the supports (avchea 5 ppabetatndi ors 
of beans and supports) are oiven rather. OO -SWaL\. One 

Mote Se We RVULtEr. APPViCatrons | of Graphic. Statics, Port. any 
LHS] GOntinuous Beow. Bivich. 1900. 

7. Pilg. 9S shows investigations. Oh oGams On. vares: cand » four 
supports with equal and -unequal panels. 

i. Beam on taree supports. ‘(Two panels) . 

a. Equal panels 1. ogee Lae ae oe 
Loading of both panels. by. aby oa Ce I ee TD ea mh 
oading | of one panel by p. ee a dit A hata gh 5: 

po. Unequal panels (Left. panel - 0.6.0r 1.4 1). : Mi Re ef 
Loading I: potn panels Loaded. be ie en EG: 
‘Loading II: Left panel loaded. ua SE ae ak mR ahd 
Loading III: right panel loaded. 
2.*Bean on four auaber a: (bec wats: oe 
a. Hqual paneis 1. ie ie : mmm 
bp. Unejual panels «(anda . panels 0.6 or di 4 ae A ae 
Loading I *: all three panels loaded. o oe | he a RIE OE A ca ae 
Loading II): end panels loaded. — ee a ey tata she 
Loading II: Middle. panel loaded. Bee 
Loading I¥r: middle and one end panel- loaded. ee ca ey ek 

Toe illustration exhibits. vhe. effect of reducing ‘OL. inereas— eee 
ing a paneljon tae form.of the mowent area | ae Pe 

3. Pixing at. the ends can. imoreade: the. positive. wonents. of BC Ne BE coal 
tne middle «panel. ‘Yet in) general» the effect of the fixing. ee a aa a 
ents on tae other parts of tae beam may ‘pe neglected. ole e et Oe 

Nove Lepoidd. Bestvaes- the apectal hei date i vaio on continuous: Sauk a pea ! 


en aes 


ecans, reference way be made Vo the folowing publications. 
B & Be 1900, -poi2d, 154, 1752 1908, HY. 250, 395. 1909, pod, 42 
1910. .BetSys -19d2y)59 «AB hs AQDiQy, De 17, 1943,p. age: Gonsrive, 
1912, pe 15k. Arm, Be 1240, .petA7s 182; 4942, p.doas AQAS, Pe 
QiQ, Wl. ZB & Be 190%, ¥.166, 487, 522; 1940, Re 28, 208, 402, 
AAS, -5O%, G06, “TAB, 1944, Pp. 18, 34, 142, “458, 2OTy Bt, 402, 
CB4. FAS, eee a 

PISS 6 one desires to simplify the obtaining of the Loads on the 
supports , then may one™ assume throughout a. uniformly distrip— 
uted Loading oy dead and live cere Let A, Bs Pe: ete. ~ desi g- 


166 
fr. 16 G es ne oe 
designate the supports, beginning at the left, taen one finas 


approximately py the aid of @lapeyron's equation, assuming equal 
spansi-— 2 it 
Note 1. ps 186. For % to @ supports, in the Taoke for Voads 
on supports D and B are inserted palues about 1.0. 
Note 2. 186. Bor very smoll end panels way result ne ative 
Loaas an the supports. in such cases oe ‘eigen ortyld ee exact 
caloulations Ore naturally . RECOSSANYs ar 
SUP es. Noé.of supports (load on supports = K 1 (g.4 ue ge 
er eee eae ean cages! Vals Re 
0.875 0.400 0.8929 0.5947 0.3042) 0.8944 0.3948 © 
4.250 1,100 1.1428 4.1317 1.1846 1.1537 SNe op 
aeees  ----- 0.9286 0.9736 0.9616 0.9649 0.9640 = 
According to tae Regulations on p. 178. (last paragrapa) the 
calculated assumption of tne connection does not extend over 
wore than three panels, went for: tae load on the widdle supp 
orts must pe inserted B= G'= (1.1 g por: p)1, corresponding 
to a panel mowent ef (0 .025 g + 0.075 pit. 3 i bine 
Note 3. peiB6. Some trues ‘Tor: Eee Loads ope supporte-- Va ay 


oo 


C2 


erence to \Wacreased Live Loaas -- “{ixeo GAEbTVONS » Cup to- 10 hehe 
are presporveed to increase - the sofety. 

for tae structural. sreatment of continuous slaps the follow 
iny is tobe stated: — Over the points: of Support the steel re 
inforcement is to be placea in the upper gone of the cross 3ec- 
tion and near the external Layer, to receive. the tensile stres- 
ses (see Figs. 95, 94): otherwise the arrangement of tae rein- 
forcemeat is according. to the same points of view, as already 
Stated. Accurate representations » of the reinforces ent of cont 
inuous slabs are seen in Pigs. 6, 97. Stirrups are generally 
CR ccudwes the bending or certain. rods follows, not on .acc- 
ount of tne shears, but indeed to transfer the Lower tension 
rods of the middle of tae slap inio tne tension gone lying Ov= 
er the supports. The. cross section over tne supports is. gener—_ 
ally wade so deep, that there tne sae amount or steel - suffic- 
es as at the middie of the panel. Frou the dava in Pig. 99 it - 
nay be seen, that the. continuity of a slab as opposed to ct 
ly resting on the supports, way have as a result an important 


economy of waterials: in consequence of reducing the thickness 


Al 


or tne slab. | | 
Note Ae PelBS. Bur Vt Vs always advisavdle to also allow the 


467 
reinforBenent above the supports abso to poss through bedkou, 
since by the uneaucl sinkings of the supports. {see Fig. 27 &) 
LensiLe stresses Way also occur velow. The \ower Continuous 
reinforcement also affords a vetter connectian of sbab and rib, 
WOKS SSeGuTe against — ShEaT. | ; : 
Fig. 97: reinforcement of a slab extending. over three pineie: 
(a). If the panels are equal, then in tne middie. panel as Fig. 
97 a snows, generally steel reinforcement must also be arranged 
at top (uniaverable effect of the fully loaded side panels). 
This reinforcement is then saved, if accoraing to Pig. 97 e + 
ine end panels are smaller than the middle. panel (at. least 1, 
= 0.8 1). Big. 97 f shows one slab. extending over two pemeles 
If Ifbeamus are euployea for the oceans, then may ine reintor-—. 
cement be according to Fig. 9 Or Bs Arrangements according to F 
iM Ho. 97 c and Gd are nov recommended; ‘tne reinforcement must: 
extend into tae adjacent panel as ‘in Fig, Bibs) << Pig. 97 é- 
snows that continuogs : reinforcement below ‘is: ; entirely, proper. 
(See Note on p.- 186). 
Fig. 98; different conditions of solid slabs. between mild 
steel I-beams. i | 
NOtS? LeDe 180. Yore extended Maia skanvens ‘of Pig. a8. Ore “to 
ve Found ww Port Li, ox im tilelatalahy 1 las fae | 
e. T-beams. ‘se fig 
vor larger dimensions of rooms are employed tae. so-called 
T-beaus; parallel to the shorter side of tae ‘room are placed 
beams, and these are ‘connected together by floor. slaos (wita 
or witkaout cross beams). it the span be too great, or ‘if one 
be exposed to: ‘important restrictions: ‘In tne cnoice of tne Str- 
uctural nelgnt, then may the - ‘{-beams be supported by columns. 
Tne usual section of a T- -beam is: evident ‘from Figs. 100, 101. 
Since quite important shears oceur ‘between the slab and tne 
rib, the rib taus. tending bo separate from tne slab, tne dan- 
gerous section ‘being mostly at the under suriace of the slab, 
and when tae section is increased by arcnes with the addition. 
of Starrups, it-is. made. tore. suitable tor receiving such shears. 
(Fig. 100). 
As tor what concerns tne arrangement of the silgbabesucas. 
then for tne -P=beams, according as tney are free or fixed at _ 
Doth ends, tne same is true as for simple slabs. Positive 
mouents require the reinforcement as close as possible to the. 


y y ae 


i 168 

lower suriace of tne concrete, and negative moments require 
Bio reinforcement as near as possible to tne. upper: suriace. 

Rag. 100 exhibits different arrangements of the steel reint- 
orcement. Fig. 100 rt represents a beam on two supports; to. rec— 
eive the shears serve. stirrups and bands in the rods, which 
sooula prevent the dangerous snear :cracks. (Fig. 67 e, ps16h)... 
fo support the bearing rods while concreting are frequently: ad- 
visable special | Supporting :rods_ ‘ln tae: compression ‘Zone as in 
Big. 101 b. -- #ig-i0i II shows a beam on taree ‘supports (wita 


uiadile. column). ‘Likewise here the. ‘roas” are. shown separately: to. 


make tae arrangement ‘oft the. reinforcement’ mere apparent. The 
connection with. the support. ‘1s: arched; for. the stiff Junction 
are taken: baree separate: arch Megs» A constpuction peeerette. 
ounile oytiead reasons. Te 
According to Fig, 102 the : construction ‘or: the. floor OL) ae 
rectangular room ‘is in: vals: Way, that a: main. girder A and two. 
sige beams B are. placed at pigat angles. - ‘Fhe distance apart ‘of 
iP beams B- ‘varies greatly, andvis particularly arranged accor- 


‘ding to tae dimensions of the- interior to ‘be Covered. It gene- 


rally varies’ between - 155 2803, Om. d ‘The less the distance ‘bet- 
ween beams, the thinner may be made the» intermediate slabs; & 
and conversely, taick ,Slabs are necessary. when the: beans are 
placea far apart. The. width. by of the bean mainly depends ' ‘on 


tae number of rods to be inserted. ~- The forms for T-beams 2 


require more expense bhan. tae: centering ‘for tae. ‘simple slabs;. 


yet tne use of a beam :féoor 18) almost always» eogunsent 1 Age 2 


ferable to that: of a continuous slab floor. 

Note. Pe AK, One shouva. Rot take. the. avetance » ‘Ketusews the 
Seams too Large, - ecavoubeaks advantages | Un reinforced. cancrete 
fL\oor = ‘SCONSTVUCTVON AaB. a eure | Onky @XV8%, ag: One. “USES | the. same. 
Spacing of ocoms aad Supports, | to. which he: vs occustoned Vn 
steel construction, ‘ | 

The supporting ‘of the beams. generally is. according io Pig: 
103; the bean : ‘extends ‘into the wall, leaving tae slab. between © 
tae beaps to rest. On the wall. In many cases it is. advisable 
however to nave a. support. as in. Fig. (103, according to which 
beam and slab- end ina. conbinuous supporting wall beam. 

Qn the structural treatment of f-beams- ‘see Section ve 


f. Vaults. 


Nt 


Ss 


169 

Vaults in reinforced concrete, besides compressile stresses 
may also receive tensile stresses, wherefore they can be made. 
thinner than tamped concrete vaults. -Their axes may be nerizoa- 
tai, inclined:or vertical (ceilings, ‘roots, bridges-and > ‘Tound- 
ations -- stairs and ramps -- retaining wails, tanks tor. fluids. 

“por. concrete vaults. reinforced ; RORERRES reinforced with Ste- 
eel occurring in’simple buildings, two forms are. to ‘be. distin- 
gulisned. Tne first of these @Xhibits the vault in ‘pota. the ia- 
‘tfados and bac extrados. (Figs. /105 a, 106), while: for the other 
principal form only the ‘intrados is vaulted, the: ‘extrados being 
olane, on tae contrary. (Fig. 106 b). Vaults of the last. kina 
are muca ‘employea, ‘particularly in: buildings, | and toey. are. ta- 
erefore to be recemmended, since they exert less Side tarust | 
on one i caahaarerst Dad also the. construction 1s cine or and as- 


Ms ib) Stat Cin Oy 
DE SGN Bite ih 


rater cen > ects AAR IB ac tat My! | 


atecn form approximates: the. viparabetar then atisees for eae. two 
principal . forums: a. reinforcement | ‘in: the intrados ZOne : (Figs. 1 
105 a, b). Hor medium and aarger. “spans: is. advisable @ reinfor~ 
cement, pota: ‘in. tac ‘intrados ‘as- well. as the. extrados zones. & 
KPige. .105 a, €). Such | doubled reinforcement’ also corresponds 
to the. occurrence of transverse. cracks, which fave appeared. ‘in 
both zones wita. a live: load on one. side ot tne vault. Tastead 
of the continuous reinforcement of the. extrados, there suffic- 
eS under some. conditions. an’ anchoring of the. extrados at the 
abutment, as in’ Figs. 105 £, ie). The intrados ; and extrados pe 
nes ‘may be. parallel. (Figs. 105 a, -e); yet ‘particularly for lar- . 
ger spans a deepening of the vault. toward the. ‘springings ‘is 
generally more advisable. . (Fig. 105— ‘nh). -- According to Fig. 
497 tne vault is Tormea. ‘into. ribs” and these. are Gamer ies to- 
gevner by closing » ceilings like. (beams, | 

Since now in: very few cases. ‘cracks parallel to the axis: et 
the vault are observed, the addition of starrups to receive 
any @xisting snaears is generally unnecessary ‘in: simple build- 
ings. But a Strengthening by shanks one od to be recommended in 
Fig.-105 d, e. | | 

Always to be considered is a complete unyielding of the abui- 
nent; ever so smali'a yielaing of tais bo tae existing norizon- 


he | 


170 
1190 
norizontal thrust (especially for small rise) may result in & 
the greatest dangers to the permanence of tne vakht. 
ge Supports. te | 

por reinforced concrete supports are generally required the 
least possible sectional ddmansions. It a concrete member of - 
square, rectangular or round section (most tcommon 1s tae squa- 
re section), there are near the external surface continuous 
vertical steel rods, connected togetner at distances of ZO to 
40 cm by transverse ‘connections -- wire bands» (igs. 51, 110). 
Between tne external’ surface of the. concrete ang tae ‘reinforee- 
ment mast be a sufficient distance, so that the concrete is” ‘in 
_p Wgpat than to prevent bending and rusting of the rods, as well 
ei to afford an effective protection. agaisot the ‘neat ‘of ia fire. 
The reinforcement. mostly consists ef round rods, woica are. syu- 
metrically distributed in the: ‘cross section, and are arranged 
parallel to eacn otner. -- For continuous supports, - to make a 
easier the erection of the building, tae butt - -Jjolnts ‘in. the 
longitudinal rods are not placed in the lower. column (Fig. 108. a 
bat in the upper column, asin Piga 105 b; also see Pig. AOL. 
-- An example of treatment of tae dase ‘is. shown in PIB. 109. 
(Also see:Fig..19 on pa 72). ° gh oe : : 

further see Section XV as weil as Part Ii, ve ua edition, sec- 
tion 1 iB, “MP. «47 60153. | Ee: 

On concrete columns epitally banded ith steel, see Seasion 
XVII. % | 

Fig. 110 exaibits the general arrangement and the distribat-\ 
Lon of the steel for a larger floor desiga, consisting of floor 
1 2bs, ain and cross beams and supports. The floor rods are 
carried over the beans and are. ‘nooked together tnere. zt Likew- 
ise several rods of the -bemm are carried above the supports +\ 
and anchored in the adjoining ‘panel. Main and cross beams snow . 
stirrups, whose ‘ends are bent (see Fig. 100). The supports are } 
reintorced as in Fig. i01.and are Gurnisned -witn cross bands, 3 

Norte 1. ei1%Se-Suck an anchoring of the steel wowever, is not 
%o be recommended, See BiG. BTC OnG Pe 163, Vast Lines, ane 

Hh. Various treatments of the usual forms of floors. (Pig.iii) + 

Kote 2. psi®S5. For further dato on these, see Part 11, 7 th 
@EVEVOW. “Pe De oy 

a Simple solid slab:fixed at bota sides. 

bd. Simple solid slab freely supported. 


=~ 


6 Ses ae he 


mans 


eS, 


71. 

ce. Vaulted solid slab. 

a. Vaulted solid slabd:witno: plane top sevtsael 

e. Ordinary ‘T-beams with visible ribs. 

f. Ordinary T-beams with suspended ‘Rabitz ceiling. 

g. Brick and steel slab (reinforced | ‘brick. floor) with and ito 
without ‘compression: slab. | e 

fh. Ribbed slab. with, inserted light bricks. and a visible. con- 
crete ceiling. } 

i. Riboded slab:with. inserted ligat. bricks laid. ncaa sna on 
tae centering. se Mek 

k. Ribbed slab with hollow blocks on plane concrete | ceiling. 

i. Ribbed slab with inserted zollow blocks. 

me .Ribbed | slab: wito inserted: hollow blocks laid. darectly on 
centering. . 

ne. Ribbed slab with inserted. hollow blocks: itn (projections 
below to avoid any ‘concrete ceiling. ai 

PLY, | Ribbed slab with «ribs: remaining visible. (aotion. slabs); 

bne » (sheet metal). forms are removed. " Hy 

p. Slab ceiling of beams delivered: ready for use, without a 
and with separate compression’ layer. — 

qe Slab ceiling as before, but witn nollow blocks. tying bet 
ween-it and a later concreted. ‘compression. layer. ait 

is) Some -Rules. for: ‘Graphical Representation of Reinforced 

Concrete Buildings. x a 

Tae drawings ‘must- be in line-as ain description clear aad wate: 
ficiently: plain, ‘1 to snow all details. or. the reinforcement. 
Superfluous dimensions are to be omitted for sake of greater _ 
clearness. ‘In: particular ‘cases, the. ‘building : officials w211 oJ 
require’a @rawing of the forms: intended, as well: as” drawings 
for wnusual and’ strongly. stressed structural - ‘parts, andialso. 
for methods of :construction protected by patents. | 

Nowe «4. ‘peid6.- Important | vs. the pesubation. “ey vae- President 
of the Burilarned Off rece vn Bervin, | of Bec. 19, 1918, 
“in recent times have eon! vepeatedly bean vrought-to we hae! 
ALVERN § cabeulations. ONG explanations Yor certain avohitectural 
constructians for checkin’, » Low which the. ‘SVAMPSS notes are Wort 
ovear or were already faint, or an which. the Lettering with ia 
anvVine or HK pencils could not be read by artificial Vrenrt 
OW aBoount of its SLosse Generally the written portions were 
On Loose sheets-or ouby Weba togetter vy Loose angle clips, = 
and produced without numbers. ; 


Stoo 


i 


ee 
oe eb 


s “172 

Since such writings wake very avifricult the regular treatment 
Va the business procedure of the Burilaing OGfice, or are even 
WLR ervy wnsubitovte, I have a\rected. thew %O be Teturned Vane- 
Gately. Bherefore L request owners. and contractors in. their 
Own DAtETeYsts, tO only boring SuGh GOCGuments, that ao MOT, pres- 
@nt these aefects. * 

For simpler buildings are first necessary ground ‘plans, eer 
possible at the geale of 4 ly 50. The cross sections of reinfor- 
ced concrete floors are to be drawn in dlack- jwithout. Ligat. ed- 
ges), stating the thickness, the subdivision by ribs, toe ‘rein- 
forcement per mn, i width of floor, etc. Separate drawings: for 
the ordinary floor slabs are. generally. unnecessary; bere suft- 
ice inserted sections as ‘in Pig. 112 ae The underside of the i 
or is drawn, taus all ribs are‘in full lines. (vault lines 
er, see Fig. 11Z.e), The steel rods are drawn separately. — 
but Pox tne structural superintendence costly suffice simple 
representations as pee Fig. 112..b; above the floor is given ‘the 
taickness of the concrete, -pelow it is. the reinforcement: neces-~ 
sary for the middle of the. panel. A similar. metaod of indicat- 
lon is shown by Figs. iize, f. in the ‘illustration last ment- 
loned, the dimensions of the arches are also given, and. in Fig. 
i1zZ @e, also tne distributing rods. Pig. 97 presents drawings 4 
for floors at a> ‘greater scale With: “separate steel rods. Lf a 2 
particularly accurate drawing. ‘ais. required, ‘several sections = 
may be arawn as ain Hig. 115. 4 3 ae 4 


ae 


p. nents 


ey 

Note 1. pe. 198, ‘But in general.to draw. the steel. separateyy 

os VW PVG. 27 VS Wore cOoMMan. Gnd Wore ‘Sultavle. e ae! a 
* For tae girders: separate drawings: are generally necessary, 


to snow ‘ail ‘rods, distances ‘between ‘Stirrups, bends, reinforce- ee en? dh 


mént by stirrups, oblique. roas at. connections and heients. An 


example of this is snown by Fig. 100 (p.i90). All rods are ar= he. 


awn full, therefore not hatched. (one regards the bearing: lage sts 
made of glass). To obtain. greater clearness for. the bearing ly 
rods, according to. Fig. 114 k, the veiniorcement. ‘is only arawn 
for one-half; also see Pig. ‘LO1, wrk, for this. In Fig. a2 a, 
b, @, £, dimensions ‘and. rods of the girder are also given. jor 
example, 30 4% 48 signifies tnaat the width of girder is 30 cu, 
e1gnt to top of concrete tloor being 48 cm. In Fig. Lid sLEE3- 
» 2180 given what steel is to be pata Ue COR S is to remain stra~ 
“GGhte In the special drawings according to Fig. 114 i, one can 


£lve suificient clearness for tne bending by corresponding 


Nf 


Pesan 


aN, 


173 7 
iigures, Tae dimensions required for A f-beam section are shown 
by Fig. 112 g. 

According to Fis. 112 h the fooor and beam ° reiniorcement are 
to be shown separately. If one draws separately for both cases 
tae rods, 1 ine clearness of the representation leaves. notaing 
more to be desired. It is always advisable to place the. Lower 
tension rods below the drawing of the section, on the contrary — 
the rods of the upper zone being placed above it. (Fig. 12 aj. 

Note 1. P. 199, The example An ‘PLS. 4142 4 As graptically .ex- 
ecuted tn a\ details in Part IL, 7 th eartion, Po 44, | 

Representations of supports end of window lintels. are nbd 
nted in the plan, Pig. 112 c, d. 
| peg FORCCERIBE the data:of steel -reinforcement ‘in the. separate 

Grawings, reference is wade to Fig. 114 a, by qd; With @ varied 

reintorcement of the beam accurate. drawings are. indispensable. 

(Fig. 414 da). Between the: bearing: and. distributing rods” (shown 

in section) are left a small. ‘space. (Pig. 114. a). The sections 

of the steel require ‘no. Tight edges, but always” the middle. ax- 
is (for layind off the dimensions ‘by the dividers), Diameters 
of st&el are: ‘eiven-in mm, 811 other measures’ ‘being inem, 
Stirrups ror beams canbe indicated as in. Pigs. ia b, ié, Bee: 
double lines - {(¢) are advisable. ‘only. for details. at larger sca 
le (for example. 1:5) or for architectural » drawings: at a ve 

Size. The same is: true. ‘fer: the wire bands for reinforcing sup- 

ports; Fig. 114 © gives. examples at large and small ‘scales. — 

(See Pig. +101). ae ae 

Graphical illustrations of the end Hooks and bends: of ‘the 
bearing rods are presented “in. Fig. 414. f. The rounding of end 
hooks is recommended - ‘particularly if. the rod ends wWitain a ‘pan- 
el, thus between other. ‘Continuous » rods; witn. the “incorrect. rep- 
resentation given-in Fig. +i14 £, one does not know. Tne GRee the 
ending rod comes irom the left. or rigat. aah 

of particular importance — is. the tabulated bill. or ghaau’ 
must contain: diameter, number, length to be cut, sort OP: 

(location) and sketches with lengths as in. Fig. 114) Levan: exan- 
p le of such a Table is!shown ‘in Fig. 115. i According to this 

bill of steel then folbews the order for the. work and the ben- 

ding of the steel. Ty tne steel bill must also be noted the - 
stirrups with-all requirements for the fable (thus also inclu- 
ding sketenes and number of pieces) 


al 
ro) 


174 

Mote Le Ve 200. Seo Beorton-Kalender. 1915. Part Tle Po 162. -= 
scabe dimensions of the steel ore naturally not necessary -here. 
eee Fig. 144 V)- 

On the superintendence sheets tne sections will be given in 
plack. For plans at large scale tae cut surfaces may be finely 
hatched, and thus -- by a corresponding choice of hatching -- 
reintorced concrete, tampea concrete, lacing ‘concrete, » paieg 
way be kan: oie ‘(See Fig 116, also Fig. 402 in Part II, 

7 th edition). | 

Koto 4. Be 20%. Tf wiue prints are wade Vater, ES ok 
may be Bone with Lead pencil. The pencit\ Vines then appear Li- 
gnrter a contrast to the Lines Grown in black. -- Too bola ana 
close natching way reduce the clearness of the. Arawing very much. 

Otnerwise are given the following rules; -- tae anrangement — 
of numbers (for example, position rz) on tae Construction dia- 
grams may correspond to taose of the statical calculations be- 
longing thereto. ach roo, each important structural member 
must be specialy drawn. Ali detail arawings: pelonging together 
must be placed on one sheet, if possiple. For the purpose of 
checking statical calculations #s necessary a general drawing. 
at i: 100 or 1: 50 with included reinforced concrete floors, 
as in: Fig. 112 e, and in a given case also a detail drawing as 
in Fig. 97 or Fig. 113 (as an example for all other construct- 
ions. Sections given may > preferably be given accordns to Pig. 
114 k; errors concerning tae parts not sectioned are as gooa 
as excluded by consiaeration of tne corresponding sectional 
arawlAge . : 

Note 2e Pe BOL. TVS Grawing also fowmns the “ass far. the. ae 
CUVGULATLON Of ‘QUGRTVLLES ONG - obtaining the costs. 


Table on p. aes 


Number. Pieces. Diauneter. Noetion.  xketeh . Welignt. 
ia 120 10 mm. 3-40 m (Pig. 115). 248.68 ‘kil. 


le 116 iO mm. 4.10 u ty 290.41 kil. 


PEt! 
Sana 
eat 


175 
Section Vii. Strengta, Aliowable mee, Results 
of &xperiments. 
Toe Official regulations of tne aifferent countries in refe- — 
rence to tue allowabie values of resistance are quite different. 
Wey Table on p. 22%, 225). They give in part fixed limiting 
values; but partly tae strength is made dependent on the cnos— 
€n Wixiag proportions, on tne degree of vibrations to be expec- 
tea Tor the structural member concerned, etc. Accordingly it 
mast always:be the aim to create structures with a sufficient 
aegree of safety, all the same whetaer tac dead load is” great 
ana tae live loaa smail, or conversely. Fikea mixing properti- 
ons aré nob required, but definite strengtas. (See p. 67). ey 
basal for all determinations are, in addition to tne acrtna re ce 
experiments of the specialists: -- 


a. Publications of “German Commission on Reinforcea Concrete? ak ye ek 


(See p. 3). Wm. Brast & Son. Berlin. A toval or 29 Aetts: ute rou | 
May , 1914.* : eae a Mae atk RO. 
Kote 1. Hereafter designated by D. As 2 a ge Re ce ae 


bo. “nesearches in the Domain of Reinforced Concrete.” dace’ Be one ee 


pe 3). Wme Brust & Son. Berlin. Total of Z4 Hefts: until lay, Pay) | Cela tame 
1914. | re et 
c. “Contributions on Reasearches in tne Domain of. fecineering.” 
Puolisned by Union of German ingineers. de Springer. Berlin. in 
these contributions appear the Keports of the Commission on ‘Re- 
inforced Concrete of tne Jubilee Foundation of. German Industries. 
a. Contributions on Experiments made by Commission on. Reinf-— 
orcea Concrete of Austrian: Union of Engineers and Architects.” eg 
a. Resistance to Grusning of Concrete and of Reinforced ve : 
Concrete. ) eh Ay 
The principal means af \ja@biad ef ueongcetarss eonuek by (163). 
resistance to crushing. Crushing forces always exert a burst- 
ing effect on the concrete. Most official regulations. here make. 
a diiference between compression .by flexure and that by purely 
normal crusping. The:former is almost without exception nigner 
taan tae purely normal compressile stress allows. In the rule 
ban 1S prescribed, tat the degree of compressile strengtn of a 
concrete snail be deterhined by the so-called resistance of a 
cube. “ This is @ependent upon tae. combination oi the raw mat- 
erials, the goodness of the crushed stone, tne mode of mixing 
(machine mixing gives higher values for resistance (see p. 136, 


f oN 


176 

Note 3), aS a rule, crushed stone gives a higner resistance to 
crushing thaw-coarse gravel, as well-as sand of mixed sizes of 
grain. ¢ se dh eat is also a reduction of the water added. <3 
(See p. 40). ree ee 

Mote Le Pe 203. By resistance of a cube (see pe 120) V8 +0 ae 
be understood. the crushing resistance » of a cubical wass. The ; 
DAUWSPLCAL VALUES Of The Vesistance G@epends on the form: Of. whe. we pein 
test bLoCK, espebcally on the rato of VWs sides: (40 VA. eT : , 
Tf wais Prato ee swab (mortar - jours), then she cvushing vests- ARS a ea i 
stance Ve High, WH the converse: CUSe mR The. Kracture yesults Z Se ae 
frow exceeding the resistance o> shear. See the ‘Besay of Mca, 


BResults of Bxperimeants on the Crushing of | fioncrete. eubess (cole 

Lectvon of results, AvM. Be. 1944. p. 127, 248. ek ee 
Kote Je We 203. See page 37, AB. ys 
Kote Be Pe 203. AGcCOrding tO. experiments of Bravonat on the 


i eet, 


resistance of concrete, whe wost Favoravve | OddLtVon . of water 


\ies between 15 and 17 pec. Of the volwne of cement and. -gond 
Fig. 117 gives the graphical representation or ‘the.average - Nie 
results of gravel - concrete (23 days) ‘any whe working years 1907 eae 
to 1910, obtained at the yateriais Testing Laboratory at: ‘Gross= Mi 
Licnéerfelde. Cement content and resistance pretty regularly | ue ee 
diminiso with lncreasing . content ot aggregate in ‘tne concrete, — pik 
i.e., with increasing leanness of the mixture. The average Nes eae 
lue of me 200 kil/ouw* resistance of tne mixture 1:5 is the 
nean of limiting values from: 106 to 310. kil/em* (all cubes’ were ee 
» Bape in the. testing Laboratory, and according to tae ‘standards ee 7 SU Gres 
eee comparative crusding experineats with tamped concrete. -- 
in tae diagram (Fig. 117) is also included a: comparative Nias 
for tae average ‘values of the ‘resistance to crusning ‘OL gravel : 
concrete mixtures, such as may be expected from ‘proper making — 
of concrete and tae use of tne best raw materials. ~ a RAGAN | 
Note 1. Pe 2A. AS Proof of the possibre yariations Lor. the » a 


Tesristance wobues Vn Crushing tests, tose by the Motervals Tes-_ 
ving Lavoratory at Gross-biehterpevae | Qotatneds -- 

Mixture 1:3, vesriertance vetween 180 and 311 kivlon’, 

Mixture 1:8, resistance between: 412 and 228 % willow. 

Mixture 1:8, resistance between 84 and 237 kiV\ow* . 

Tne resistance of a cube increases with the age of. the conc- 
rete (see pe. & 112). Bxperiments have shown, that tae increase 
in resistance nas often not entirely @ndea aiter 6-years. 


177 

Note 2 Pe BZA. According to Contributions of the French Con- 
missbon for Reinforced Gonorete, there are varia for reinforced 
concrete Wextures the following relartioana: -- | 

Age ; 23 20 365 days. 
Comparative resistance 100 150 250 .per cent. 

At tne Munderking concrete Bridge, it was found by tests, # 
that the crusfing resistance of tne same concrete (i: 2053 5) nad 
nore than doubled after three years. The resistance of 202 kil 
/on* after 7 days. rose gradually to 570 kal /on? after § years. 
(See Fig. 116). 

Gary ne cigcatGadl Ciaavontaaieeiittesis ere. a mortar i 
i:3 and f1fferent kinds of cement a crushing resistance of 
122 (390) ° kil/iem’ after 28 days. Thus tne resistance of ‘concr=- 
ete 7 days old was about 70 p.c. of the vTesistance of concrete 
28 days old. , SiGe: 
as for what first concerns ine ‘compressile stresses 1a rig! 
p tae the Prussian kegulations prescribe the. following. 

“For structural members subject to flexure, tne compressile 
stress in tae concrete snall not exceed a sixth part of its. Qe 

crusping resistance.” d 

Note Le Po 20d. An upper Miwrt for the. allowaole conpressive 
stress WW the cancrete is not given by. the Prussvan Reguvatians, a 
Contrary tO. the regulations | oF ortbher. countries. : ) 

Here and in the following Sravel or crushed srgke tacKenaee i 

\s generally considered. Pumice concrete (see p. 45) has Vess 

sivendth. Grushing experiments On an extended scale are stil\ 

wanting, yet for wixing proportions of 1 cement + 2 quartz sand 

+ 4 fine pumice gravel, ane Way assume avout 120 killon* as o- 

Vimiting value for resistance. ALVowaorle cGupnessite stress ts: 

then = -s- = 20 kil\ow*, according to Prussian Regulations. | 

fous reference is to be made to the crushing resistance, and 

a sixfold security is to be. taken. 4 vor ‘mixtures 2565 t0 +524; 

tae crusaing resistance . after 26 days. amounts 128 abou £60 to 

z00 kil fens, waica: value bhus. corresponds ive) ror to Ten = 30. 

to 44 kit dene for bending. 

Note 2. pe. 205. put whe saftey for. the steel is only 2.0. %0 

2.5 fold, according to the usual wode of calculation. 

by numerous experiments it is established, that the caicula- 
tea stress in tae concrete is often considerably greater than 
the resistance of a cube of the concrete, and that the values. 


Ef Pak 


178 

only approximate in tne vicinity of the ineaiene limit. 3 Like- 
wise it has been proved by experiments, that about 2 (to 3) » 
per cent reinforcement, an increasing load on tae beam or slab 
dees not produce fracture by preliminary crushing of tae conc- 
rete, thus by exceeding tue allowable stress in the concrete, 
but by exceeding tne elastic limit of the steel, that thus in 
the structural member in flexure wito toe usualx amount of re- 
intorcement, toe stresses in the steel generally indicate the 
degree of safety. One 1S more dependent on the material safety 
of tne steel, and must then endeavor to. make the fullest. poss- 
ible use of tne steel cposs section. 4 

Note 3. P-205~5. ACcCOPGINE to Euperger for wvodies under « beveeete. 
Lae Crushnrng ‘Vesvstance Vs about twice as great as the resist- ‘a 
ance of cubes, and the requived waximun Limit of 4\6. she orush- 
Ing resistance Vs equivalent to Li-f{ola SR EOLS » LaAVso gee Note 
ON Pe 43)- AGCOTFALAE to experiments of. ‘he German. Commission 
(Heft 417), the bending resistance of a wixture : AL 2.3 3 and. of. 
42:4:83 V3 1867 pece Of the. resistance of a cube after 28 GAYS. 


Scntle found the calculates CYUSHIiNG | wesistance of concrete: AW 


eeans ubsout teh t0:224 OVE. tate sn cubes. The usual caleulat- 
von (negvectvng- the. tensile resistance in the concrete, vevnf - SAE 
orcemens of 2 .pece), thus Leads to on over. estimate ng the som 
PressilLe StVesses VW CONCTELS» he : 
Note 4. -pe205. NEVLOY has. proved, Nod! Vt V3 wort adi: Xo. say 
for the safety of 0 structure, VT: the. test of a cube remains 
somewhat vetow the vequived resistance, that a. rectangular or- : 
033 Section Wust ke vrertnforced up to 3 Pee, Unt Tiwalby. Ane a) 


COMPYSSSILE StVess WW the Concrete is determinative for the = 


safety against vreaking. Gontribs. 12912. p.186, Vso. See. Bete 


of, Union of Architects Qnd Baugineers. 1912. p. Bq. nae 
P. Pr one counts on 9O days instead of 25 days nardening of tae 
concrete, then:one may calculate wito limiting values of 252 t6e 
50 kil/em* (see p. 204, 122). Attention is called to the French 
end the Hungarian Regulations (Table, p. 224), which are by & 
far less nard than tne Prussian Regulations. Likewise to tne 
Wurtemberg Regulations (fabel, p. 224), according to which the 
Limiting stress values are dependent on the degree of expected 
vibrations. The Swiss kegulations even go to 70 kil/en¢, while 
indeed the stress in steel is reduced to 600 kil/em*. (P. 222).¢ 
Hove 1. pe206. The Brench Regulations allow 28 per cent of 


VRE Yesistance of a cube after 20 days, whieh with o 


179 
resistance of 250 kitlon* é\ves a stress value of 70 kitlen*\ 
Note 2.92206. 1% thus appears advisable to take higher valwes 
as allowaobe compressibe stresses in the concrete, than ove S 
aveen vy the Brussian Regulations. Attention shoulda. abuays be 


stress f 
calbed to the fact, that a WiGher Vinktind seniors with an unce 


-nanged stress nm the steer. wakes necessary a greater veinforce-_ 


went. (See Section VILLI). And thot thereby the safety against 
{formation .of oni aco kia ehulc 


VS reduced. 


Dyckernoff & Widmann, Carlsruhe, loaded a reintoreed. ‘concrete 7 


slab only 4.5 cm taick, continuous over 4 steel beams, 4. mont- 
os old, witn«i100 kilAn“ live load (11 times ine- calculated 2 
load of 100 kil/m4),witnout fracture. Spans 2.0 m, total loaded 


area = 23 n¢, greatest deflection in tne two end panels S65 Mies: 


ana 5.5 ci. After complete remaval of tne load tne debhacepen 
was reduced to 7.0. and.4.5 cm. 7 : gle 
On tae permissible resistance of supports tolconaresuien” 2 


toc Frussian Regulations prescribe, that tae concrete shall’ 


not be stressed more than 1/40 its. crusaigg ments ieee ‘Accor- 
ingly tae allowable values vary between --- and --- = 18 and A 
26 kil/em* for pure compression. The required factor, of safety 
10 is taken hign. It would correspond more to tne facts to le 
a swalles factor of satiety (for. example 5 to 7), while at the 
Same time for not reinforced. concrete supports ‘is’ preseribed — 
a 10edold satiety. 4 
Note 3. po2OS. On this see Sections X¥, X¥1,_ XVII. 


Note 4eP- 206. Stresses of abvourt<30 kibl\on® wianrt thus be, oe ; 


ee? 


Zaraead as allowable for supports. > “According to: Sues preceding 


li for pure compresston is permitted a Vomiting ae : 


35 kib\ow" «(Purther See Gontrivs. (1908.88 Mo. a. 

’ Decree of Prussian Wiinistry ‘ot Dec. & i910: -- “fhe haximun 
compressile stress in. tamped concrete for a quiet. etn byst Q- 
hot exceed one fifth of its. crushing resistance atter 2 VS. 
Ror supports and piers tais. stress. is reauced wita seesaaek 

atio of neignt to: least diameter, and at most is. to .be assumed 
i/6 of the resistance for ratiou1: 1, 1/40 for. Patio 5 ra Bh 1/20 
for ratio 10:i. Intermediate values are to be interpolated by. 
Straigat lines. Tensile stresses in concrete are to be negiec- 


ted in tne calculation of the maximum compression in the angles.” 


Also see Arm. Be 1911. p. 68. 


Bee 


L180 


According to Bach’s experiments for obtaining the compressile 
resistance of concrete columns witaout reinforcement wita dif- 
ferent neigats (Contribs. 1914, Ro. 5), the reduction of tae 


stress, neea not go so far. On the ground ‘of these experiments~— 


considering the inaccuracies 1n the work -- one Can count on 


about i/6 for tne ratio 5:1, and about 1/42 for the iionad 
But bigner al allowable stresses for slender columns taan '30 to. 


35 kil/en are not to be recommended, Since it is to be consid- 


ered, that the load in‘ general does not always act axially or 
uniformly distributed, as the calculation assumes. 


for supports, taat extend through several stories, it an in- 


crease of the albowable compressile stress were in place, and 
in consideration taat only the upper toin supports migat rece- 


ive additional stresses 1n consequence of their rigia connect- 
10n wito the beams, and that for tae supports of the lower sto- 
ry, a full loading of all story floors can scarcely come, ing \ 


question. (A reduction of the live loads according to page 163 


uust then certainly be omitted). Thus if one takes the differ— 


ence from an exact: caiculation oi tae additional stresses, then 


one might begin with about 20 kil /en¢ for. the supports in toe 


attic, and graduate the stresses downward to about BO kil/emt ne 


tor tne cellar. piers. ‘MOrsch even estimates. 2) to Ee kii feat, 
beginning from the top, as allenanie values ot resistance. 
(See Section XV). ‘ ’ 
b, Loe 
rete. 
Note 1. p.208. AVEO gee Section MILL. 
It is generally required, that ail flexure tensile stresses 
acting in reinforced conerete members shall be resisted ‘only 
oy tne steel reinforcement, and thas | any tensile resistance of 


tae.concrete 1s to be omitted in tne Caiculations. Yet the Pr- 


uSSlan Regulations prescribe; -- 

“For buildings or parts of structures, that are exposed to 
weather, wet, smoke, gases, and other injurious influences, it 
is Turtaer to be proved, that tne occurrence of cracks in tne 
concrete from the tensile stresses acting in the concrete will 
be preventea. 


b. Tensile Resistance of Concrete and indie oe 


if in the designated cases the tensile resistance of the con- 


crete 1s taken into account, tnen as allowable stress is to be 
taken two-tairads tae resistance of the concrete to tension sa- 


LOS 


151 
shown by experiments in tession. With lacking evidence of tne 
tensile resistance, the tensile stress must not amount to more 
than one tentn of tne resistance to. compression.” : 
For example, if a crusning resistance of 200 kil/cm* be obt- es 
et for a member in fiexure would be:-- y A i” 
200 Ge Reon } 
Ong = ==> = about 33 kil/on?. 
One = = = about 20 kil/cm?. 


(According to. the Regulations, this stress uyat- correspond 
to a tensile resistance of at least ee x 20 = 30 kil /en*). 

For the usual»cases ‘in buildings, the. participation of tae 
tensile. resistance of the concrete scarcely comes into. consid- 
eration. It is much less than tae crushing resistance (1/40 to 
1/45 of that), and- 1s greater for a rich, than for a lean mix- 
ture. According to experiments of German commission - (Heft i7), 
tne tensile resistance of mixtures 1:2.5: 5 and -i24:8 after 2B 
days amounts to about 92 p.c. of the crushing. resistance ot a. 
cube. As an allowable limiting value may be taken about 15 to 
20 kilfem*. ¢ Altnouga the occurrence of tension cracks in con- 
of te ao not cause the destraction of the beam, yet the €xist- 
ence of 4 ies cou vensile resistance of the conerete 1s al- . 

Note 2. Rat These: Vamiting. values have walue ony ne ave 
Culatlons, Bince the vensbbe stress. actually OCCUPY ing | with i 
the assunptrion of equa changes . of form. for CORP HERS hae and 
Vension (Brussian. Regubatians). Cannot. oRount vo wore. vhonjone 
Daf of hose calculated. The Suiss- Regulations thn) 40 won? . | 
as the Vinvting value for. tensile stresses at. une ChG2 of eco a ao 
RLV LOAVby compressed BStvuctural wenoers. The Vimiting values. 
yor vending GAG eccentrac ‘compression Qvoen ‘ey the Austrian 
Roan \ ash eas RB SOE eee to. the Wixing Proportions (22 to. 25 AL 
\on* are Found in the. Tove On. De 224. UN cancrete members not 
reinforced 5 killom” at wost is. to ve taken as the allowable 
Lensile stress. cannes 

On the ground of a Meta of Labes’ rule + 
relating to tae calculation of tensile stresses, On the basis — 
of the results of flexure experiments, ‘EbCe, the following nave . iy 
been establisned:-- 2 : ae . fag i (5 BE 

Note 1. pe. 209. Loaves, “How can. the use of Reinforced Gonore- : : 
ve Vn Railway Administration ve substantially requebed?R 


* ‘ ’ 
4 : 
a a oN: a 


Poon, 


15z 
Gente Ge Bauve 1906. No. 32. 

Note 2. See B& Be 190%. Pe 157. 

Note 3. In the wroinriy Of the reinforcement. tne MBVAJUP SG 
CONGKStS COW St~VIL Sustain a tensile stress of 40 to 50 wil\ow*. 
-- One Can assume the tensile stress in flexure nhs avout double 
the pure tensile resistance. 

i. Tne calculated tensile resistance to flexure for tamped 
concrete work is smaller than that for reinforced concrete. 

Ze. Tne tensile: resistance to ftiexure increases with tne amo- 
unt of reinforcement, with tee better. arrangement of the ross ; 
section, and tae roughness of thé rods. 

5- it likewise increases with tne age of tae concrete. 

According to fetmajer’s experiments on test pieces of concr— 
te and of: reinforced - ‘concrete, 1.5 years ola, tae vensile res- 
istance to flexure 1s Considerably greater than pure tensile 
resis tanceg, the steel reinforcement seems to substantially in- 
crease the tensile resistance to flexure. (ara, Be 4942) ay tae 
S81, 120). | 

Pure tensile resistance of concrete but seldow comes Re A 
tion tor the calculation of ‘compound memeers, ana can only be 
approximately oDtaineéd. 4 

Wore 4. Po 209. Main difficulties in test Dae direc 
tion of force acourately | VA Axis of Lest prece, be vaginaiagie's ena- i 
Une moments. (Kort avVowable tes% va\ues). Ae s 

Bach 'Touna Joy. experiments | tensile resistances of A7.35 ona 
25440 ‘KAL\ow*. (AS! ‘a\Vewaobe Limiting yalues One mee: Boh dh “about 
2 %o 3 wv\om* (with. methee sai Sates). iit ge 


Ce Snearing Resistance of i ee and Reintorcea concrete 5 "i 


Note 5 De Pe 209. A\Vso see Sectlan XLII. ' 
p Proger consideration of shearing forces in reinforced concr- 
lo, (by stirrups and bends in rods) is one of the nost impor- 
tant points in the work of designing. According to the. exper- 
lments of Mérsch, Bauschinger, etc., in all cases the Shearing 
resistance of the concrete is about 1.2 to 1.5 times greater 
than its tensile resistance, and as in alli otner resistances, 
is larger for rica, than for lean mixtures. by experiments or 
the Garman Commission: (Heft. 17), toe resistance to snear for 
mixtures 1:2.5:5 ana 1:4:5is about 1343 per cent of the resis- 
tance of a cube alter z8 days. For a mixture a0355% tos Shearing 


153 

resistance was found about 4) to 35 kil/cu*. The official all- 
aaa bic pelek or 4 y) eal /eu* toen sted to acout y) to 6 
in each case to pubestiee no fixed limiting value for all cases, 
pat to make the value dependent on tne required resisaaace of 
a cube. | | 

Foe Austrian Regulations make tne allowable limiting vaiue 
dependent on bhe proportions of the mixture, tae Frencn and c- 
Danisn Regulations on the allowable compressile stress, anda a 
» bie antemberg kegulations on tne intensity. of shocks. (see _ 
fable, p. 224). | 

The shearing resistaace of beams under flexure is. | generally 
less than the shearing resistance obtained by direct shear. 
Pure snear selaon occurs in reinforced: concrete construction. 
Gn tae ground of ais. experiments. for obtaining tne snearing 
resistance 7 9 Tron the ‘coupressile and tensile resistances, 
wSrscon nas estaplished the equation To ae 4 nee 

Note Le Poezii. Aone Fines. only oneshal{ these values. | arms 
Be AVLL. Po 2AVe 


The Wayss & Hreytag-@o. (Professor Breck) duce! Gow! experi- a 
ents on pure shear. By means of a war tens’ press and accoraing 


to Fig. 114, prisms of woncrete witnout reinforcement, 140) Ch 


jong and 16 x 18 cw in cross section were vested. (See. pae125). 


it was found: -- 
for 4:3:, 14 pec. water, ve) yearn, ‘old, about 65. s xi fone» 


— 


jor 1:4, 14 pec. water, 1.5 montns ola, about 3/.4 iijeue 


for reinforced concrete test pieces Was gbdtained a resistance 


so about 35.5 kilfiem* at tne ‘age ot 6 weeks. Mérsca finds no 
 Ss>peration of concrete and steel : ‘in resisting pure shear. 
Mote 1. Pe 211. See NBysok, Bevaforced Concrete: gonstructian, 


In this work are sharply Separated whe Two conceptions, Myesis- 


tance to shove and tO shear, ‘yndeod. On BSCOUNtT | Oi, she ariter- 
ent appearances of the fracture. Wa vest pieces; werk. such a ave- 


Linctrvan Va generally unusual’ Va practices 


Zipkes establisnea, that the shearing resistance of concrete — 


1s materially increased by reinforcement. He Touna for test 
a he Digi ves 
prisms 50 days old, @1: 3 witn i4 Pe Ce water, 25 kil/em* for 
concrete without reinforcement, and 57 kil/em* for relniorcea 
concrete. ¢ 
Vote 2. pe®ii. Bepkes., Resist.nce to shove and shear of re- 


LNT Orced concrete. A 


Satie 


184 
A CYVIVOVSmh Of thers puolication is contoined in .B & B, 1906. 
Pe 289, (By uBrscn). 
d. Bond Resistance between Concrete and Steel. 3 

Kote Se PeZil. ALBO see Section XLII. 

The actual existence of a bond resistance between concrete 
ana steel most simply resulis from bending experiments with 
reintorcea and non-reinforced concrete slabs; for the former 
slabs show a substantially: greater Supporting capacity, which 
is only to be explained, that tne steel adneres ‘Tirmly in. the 
concrete, and contributes to the statical efteciency. 4 One ¢ 
properly here has to do with a ‘purely mechanical effect, which 
occurs when the concrete shrinks in. haracning and | ‘Clamps fast 
tae relatorcement. Opposed to this. view is another : Opinion, & 
according to whica tne silicates of the cement form an alloy | 
with the steel on the surtiaces in contact. Z Whether ‘bne- mech~ 
anical or chemical procedure takes. tne chief ‘part-in. “tne ‘bond 2 
1s oard to say. 3 | : bes 

Note Ae Oe BAL. In other cases the Vasertion at the» xc: ow 


WuUst COLNGIG? with a reduction | Of he eross: section, wus atte 


a Voss of the supporting capactty. peat : 

Note SS. pe2ii. Rohvand attributes the bona of the steel tute 
the concrete to the Colors nature of the cement, by this. Re 
aso compelled at the. Bawe tine the “shytakage of see) concrete, 
See Gontrvos. 1913. ‘Be 103, ; . ; 

According to Preuss » (Sxperiments on Eond between Steel and ies 
Concrete, Arm. B. 1910, p. 539), the bond Between concrete ahd 
steel is to be referred to taree ‘causes, Hea., Se 
SRUSEXGEXKRASEING. ” be | 

1. Toe actual adnesion, i.e., sticking in tne sense of “pas- 
bing.” | ie 
; 2. Resistance of friction, that ‘opposes any ‘Slipping of tne 

Ps ‘eel in the conerete, caused - by contracting of ‘concrete ‘in 
Sétting, cramping tne steel to. a certain degree. 

3. The wedging action of the sana ‘grains, which in any Sslip- 
blag between the concrete and steel are loosenea, and tend to 
brevent any further slipping. | 

The bond resistance increases witn the diminisning effective 
‘sptN Of tae concrete section and With the increasing bercent- 
4c€ 1n reinforcing rods. As a rule round rods exhibit greater 
vona resistance than steel-oi otner sections. Tae bond is tne. 


PLL 


185 ' 
greater , tne richer the mixture, tae slower setting the cement, 
and the olaer tne concrete. Likewise the bond increases with 
the sige of grains of sand and with the reduction of pe waters 
adaed. Practice has also shown, that effects of shocks, for & 
example such as are unavoidable in factories and Pa ogg can- 


not injure the bond. + 


NOt? Le Peo 212. Yot the Wurtenvers ‘Weeuvexsans: ‘wake. We Pa 
awavbe Viwinting value of bond stress dependent an Ibe Laight’ at 


of actually possriole- SHOCKS. See Tavle on vv. 2A. 


Ag for the allowable: ‘Limiting vaules, ‘it has. been detarmbaedl io" 


by experiments, that the bond in most cases - 1s somewnat ae 
er than the shearing resistance of tne concrete; for example 
that many tests on rods pulled out of ‘concrete, particles: of 
concrete stili. firmly adhered. ‘Paerefore also in tne Prussian 


Regulations tne fixed limiting value of 4.5 kil/en¢ (for. allon- ae 
able pond resistance), wnica must always be proved, 1s. taken Ae i 


ratner low. < 


mu! Bs 
$6 


Kove 2. .pe®l2. But experiments nave shown, ee ae a 
WAS NOth Ag LO 3.0 WLS the | toad dicbhasad of. ne cancrete: to. Reducting © 


. 


see Secrtrvon XI1. 


Men have proceeded from the point of : ‘view here, ‘eaat the ‘bond | 


could no longer oe effective, if the. concrete were destroyed 


by €xcesSive shearing stress. One ust then assmue nigner vee cee 


Boye, She eet eat Cae 


ues, 1f toe stirrups and also anchoring. and: bending» of all: lon- 


gitudinal rods are arranged. (See Section XIIG. The. preceding 
principles assume 7. Di kil/iem? 
ding to a maximum bond resistance. of about. 38° iaifen? (thus a 
five-fold security). The Brench Regulations ake the mijoniuies 


bond stress dependent on the permissible. compressile stress, a ee 


and this again on tne obtained resistance ‘OL 1a’: cube, woich me- 3 


thod is indeed most suitable, since it aftords the advantage 


of a uniform safety, and creates the. ‘possibility of also incr- - 


easing the ‘pond by an improvement of the nature of the concrete. 


hngesser therefore proposes as the allowable value for bona a. 
stress (Arm. B. 1910, p.71):- 

QO.i of the iv eeavisdipebaat tte witn few longitudinal 
rods and a suificient number ‘of. stirrups. | 

0.05 of tne allowable. compressile. stress, With many longitud- 
inal rods and no stirrups. | 

Hote 1.2 pe 2ZiS-e See Tavre, pa 22h. Bacon obtained wee, Waated« 
ance to sip as i\8 to 1\10 the vesistance to crushing, and os 


as the limiting value, corresgon- 


186 


BRESVstance. S 
Note 2. pe. 243. Superger CSrtimartes 4 ‘Avion? » WLEN Separate 


YOoas, Cross ands and the Vike, 6 Wiv\ on" of “MBrech and von. ‘Baul 
Vie prefer 7.5 kiv\ou*for Voades beams wader {Lemure,  Foorater, 


ve 


estvnates FT Kib\on” as avlougple vond siress unaer flexure and 


5 Kil ou*for pure compression. Loading. is gi 


bitferent specialists, for example Probst, Saliger, ‘Kleinlo- 
gel, Preuss and Scenaiile express tne Opinion, that the | ealculat- 
1on of bond stresses way be omitted, so tar as the other stres- 
s€s ao not exceed the allowable iimiting values. The destruct- 


ion of the beam results. earlier: by. tension cracks la. conseque— 
nce of tne stretcna oi the steel reiatorcement. Likewise the S 


Swiss Regulations allow bona stresses to be neglected, and al- ina 


so tne Hamburg Regulations or 4943. ait, 


Note 3. De 213. See- ~“Kveinvogert, “On. the Nature. and true. eae 


niviude of the Bond Stress ovetweean Stee and Goncrerer Bervin. 


L9LL, “The Bossvovlity of owrttind tae. Galoulation of Bona ae A, 


resses? Rontrios. ALi, yp. 37, 66, as wed as “Studies: on, the 


Questvan of the true Magnitude : Of Bond: Resistance? Arm, e. AGL. a 


pe. 3395, ABIL, HP. 23%. 


In construction a sufficient covering of tne steel mula 
went is to be cared for. Bnd joints in the steel are to be av- 


oided, if possible (see p. 51). Some. metnods: of construction Sy es 


exaibit the endeavor to hake them independent of bond resista- 

ace, when special steel rods with rolled projections are empl 
ed (see p. 54) or flat bars with riveted angles. (i6ller plan). 
Attention must always be called to the fact, that. deformed | 


cars of American patterns can only fave the desired effect, me 


tne roads are anchored in great asses of concrete, but taat, ane 
tae narrow ribs of T-beams is tne contrary effect, when the a. 

‘aieay exerts a spiltbtings etfect on Loe concrete at toe bottom 

of the beam, so that a premature opportunity for tne tad getaiiek: 
of cracks is atforded. 

The diversity in tae results of vodie piucnaeste Nes be re- 
terred in tne first. place to the varied nature and composition 
or the concrete mass, as well. as to the different additions of 
water. Likewise tae results are dependent on the different. o- 
acs of making tests, whether tne bond be obtained by pressing 
or pulling the steel rod out of the concrete mass (see Pilg. 
i120), and wheter tne duration of tne stress ‘be short or long. 
fn general, fiexure experluents, even it dittioult to make, e 


187 


correspond most to the reality. £ According to Martens, tae ré- 


sult of a larger series of expermments are most valuable, ind- 
eed with a stepped increase of tne ema wita vacigieh Cid reno- 
Valse < oy ae 
Note 1.Pp e814. La ovdves under flexure, deber ets a 
“are Claimed to be stressed in the same sense, in drawing bey 


stee\ out of the concrete, the stee\ Vs Vn Lensrvon, our the 


cancrete V3 compressed and thus shortened. in ‘eressing | Out the 


atees (PiB- 120), the steel and concrete are stressed Vn the 
SUMS SENBSe The resrvstance obtained Vn preces Unaer flexure VS 
greater, as G@ rule, than oy preseins the vod out, and this is 
again Larger. than oy pulling Ut our. | ; | 

The correct WEASUNe of bond resistance can thus be found, 
only Vf the stress Va the steel stil) remains below the elast- 
Vo Vint, the secvron of the. steel. thus BOL “oeing Lbhone wh, 


V2AUGede 


NOt]? ZBeYesihke TOO vated ON Waorease of ‘the voading aveen: Ooo | 


favoraobe values, and can properby oe employed only for. Quack. 
PUTPOSSS. 
bach usea test prishs 3: montas ola 10 to (2 ch long and 22 x 


22 Clie With @ Mixture OT 1:4 the water aadaed amounted to 15 pec. 
{ne ewbeddea rods were partly round ‘rods | (190 to. 40 mi diameter), 
partly square ‘rods (20 = ZO mm) and in part flav bars Cit 40 oe 


to 10 x 40 mm). Tne results of tne tests were in the’ main: as 
tollows. 
i. Tne magnitude of the bond 7 depends on he aeivee (ar the 


surface of the rod. Smooth rods show a smaller bond than those 


With rolled surfaces. Rae ean 
NOt]? Be0.244- Bach designates as slip gel tir the resist- 


ance to Grawine or pressing out the. rod eer ow” ot) whe surface 


of the vod. See “Bxperiucarts .on sbvy resvatance of steel ewved- 


424 VW goncrete.” Berbin. 1905, 

Jone magnitude of bond depends on tne percentage of water; it 
increases aS the water 1s diminished. bach obtainea for +2 6'Cs 
rakee S602 %] kil/cm* as bond resistance. for reinforced concrete 
structures tae water added snould not exceed 12. $0.°15 spye. 

3. Varying greater additions of sand ana » ‘crushed Stone have 
no essential influence on the bond resistance, witoin liwited 


values. 


4. Ine greater tae diameter of tne rods, tne greater tne bond 


iy 
: 
tas 4 


iW bt 4 
LENE. 


188 185 
resistance. “ Bacn obtainea for:-- 
10 mm diameter 14.1 kil/cmé resistance. 
ZO mm diameter 15.5 kil/em¢ resistance. x 
40 mm diameter 27.1 kil/em+ resistance. a te 
Ailton small diameters increases the effect of the elasticity 
of tne steel. 


5. Tne bond resistance alminisnes as a rule with tne increas- 


ing léngih of the rod. 

Oo. Tae bond resistance obtained by pulling tne steel out of 
toe concrete test piece 1s less than tnat found by pushing it 
out. Bacn obtained for 20 cm length of experimental glock ana 
or tne rods (See Fig. 120) an increase of bond resistance of 
about 43 p.¢c. According to tnis the assumption is justified, 
that the bond resistance of a compound member in flexure is 
creater in the compression zone than in tne tension zone. 

7. For reds witn rollea surfaces bedded in test pieces coy 
cm long with 15 p.c. water, the following maximum valuesgwere 
obtained. 3 

Rounas 10 to 40 mm diameter, 20 to 30 kil/cm?: 


‘Flats 10 x 40 mum 21.7 ‘ki low. Woah i 
Flats 4x 40 mm | 24.5 kil/em. | 
Squares ZO x 20 mm | $1.6 kil/om*. 


mxperiments on Ilexure of compound beams 6 months ola gave 


for round bars from 16 to 52 mm dlaneter a bond vesinwaned. a ale 


tween 17 and 23 kil/cn. 


#rom experimeats witn Thatcher bars, baca Sen ane Bea to 


55.0 kil/em. 


pach’s “Hxperlments with Keiniorced Gdadueee Beams for deteguiey ane 


wining Khesistance to Slip, etc.” (2.0 m. span; section 30 x 30 
cH, 
Ph febeues to slip increaséd with the richer mixtures. . 
Mixture 1:1.5:2 snowed 32.9 kil /en* résistance. 

Mixtare i:3:4 snowed 17.5 kil/em* resistance. 

HOGS coated wlta Cement, as well as strongly rustea steel 
eave about 44 p.c. greater resistance to slip tnan the ordina— 
ry trade rods. + (Also see Deuts. Bauz. Contribs. 1909. p. V4 
Arm B. 1910. ps 279). 

NOV] 1.0.-216. Tetwajer cane to svmilar results. His experim- 
@nts showed, Taat for rods 5 and 10 wa AVamerter, the strength 
of the steet Ve tOO SsWAaLL La PYOPOTtVOH tO the vesistance to 
S\\e, 30 that the resistance to step vs Vimvied by the elastic 


45 aays old, mostly mixed i:2:3, gave tne following results. 


189 
Vimit of the steel. He found the magnitude of the resistance 
to sVip to be 35 to AY kidlou*, tara. B. A244. p. 84). 

Mbrsca underwook pressure experiments wita concrete euces 
with 20 cm Sides, 4 weeks ola and rods 20 mm diameter(Fic. 94). 
W1lth mixture 1: 4 resulted tne following mean values. 

29.1 kil/em¢ for 15 p.c. water. 
31.2 kilAem? for 12.5 p.c. water. 
48.4 kilfem* for 10 P.-C. water. 


The stress in tae steel reacned the maximum value of 2140 kil: 


taus the elastic limit (2600 to 3200 kil) was not exceeded. ¢ 
Sy adding 2 steel spirals around the main roads ~- for the pur- 
pose of preventing a bursting of the concrete, tne preceding 
values were increased to 54, 45.9 and 50.6 kil/en*. 

NOVe 2e Po 216. In Pulling experiments possing beyond the 
OVASEVG Vinit, LN Consequence of the reduction of the section, 
Q separatran of the steel from the concrete occurs even before 


TeachiWMNe the possriole vond resistance. On MBrsch’s experiments, | 
see MSvrsch, Reinforced Gancrete Gonstruction, also B & aks 


Pe 273. 


Von Emperger obtained by flexure experiments & bond resista-_ 


nce of 12 to a kil/en¢ for round rods. 
Also 20 to 30 kil/em< for deformed bars. | 


All roas in cee experiments, also tnose - bent, were taken 


into account. 2 : 
Note 3. pe. 216. See “Researches in ne ee 
Concrete.” LIL and ¥. Ae 
Kleinlogel obtained for concrete beams 25 weeks old, mixed 
1:3, a maximum value of 35.5 kil/icm<: 4 


Note 4. De 216. See “Researches in. the GQomatn of Reinforced 
Concrete,” 1, also B & AVDA. Po2d7.e WUrsch abtoined in ao S- : 
similar way On ao T-beam a bond resistance of 37.3 kiv\ont, thus © 


almost the same result as KVevnlogel. THe avove mentioned {lex- 
ure vabues of Bach (17.0 to 22.7 KiL\ou*) ove SULStANtVally & 
smaller, which ndecd 1s to be referred to the fact, that. there 
the rods were not anchored by bendind the ends. 

Bauschinger used test pieces 3 months ola, mixed{%:3. For 
round rods 7 mm diameter, ne found a bond resistance of 42 to. 
7 kii/em*, 

uxperiments of the Materials Testing Laboratory at Gross- 
Lichtenatelde snowed that bulb-shapes had tne best bond. Round. 


S“srowed_a ESS StANCE to-Siip—o¢ 3165 Sy 4864-85 2—ka hs 


190 
rods showed a resistance to slip of 31.8, 18.4, 8.2 kil/en, 
corresponding to mixing proportions of 1:3, 1:5, 1: t: 
@. Initial and Jemperature Stresses. 

fae so-called initial stresses are not to be confounded witr 
tae stresses in consequence of tae effect of heat or cold or 
of tne dead loading. I setting occurs in the air, then will 
the concrete Contract, especially with a rich mixture. On the | 
contrary, iif the setting occurs under water, the concrete exp— 
anas. If tae concrete be then reinforced, this hinders the ef- 
fect of tnese changes in form. The result of this is, that in 
setting in the air (the usual case!) teasile stresses occur in 
the concrete and compressile stresses 1n the steel, but on the 
contrary in setting under water, conversely are compressile = ae 
stresses in the concrete and tensile stresses in tne steel. + 
Yet under certain Gonditions, these ditierences ‘in stresses 2 


produce cracks ln the concrete, and in a tension zone fier 


ned by calculation may be produced compressile Stresses, and 

conversely, but on account of their insignificance, men have ie 

not taken tae trouble to take into consideration ain barton : 

ions these initial stresses. ¢ oy ee ep ges 
Kote 1. pe2i7. According to ewaceieietel tne shortening of & 2 

the concrete by Haraenine Va the arr (strinkage, “See Pee 30 ond 

224, Note 1) amounts to 0.0004 to 0.0005 per unit of Length, 

Vaus veing 0-3 to 0.65 ww per nw, the elongation from hordening — 


unaer water V3 Wolf as great. 


Note 2. pe2i%. Also see among others, he Vmeetigations: ot eat 
HRoaverkalt Wn B & 8. 1208.. Heft. 11, aleo Kefts 72 to° TA of Gon- ie 
tris. on Researches (Vol, ® 1, 1902, p. 92 (oriet POPUL See) 
Arm. B, 1908, po 842) and Gontrvoe, 1213. p. 29. To ee 

Temperature stresses are still less important tnaan the are aan 
ial stresses Guring the process of hardening. For variations 
of temperature occur no unfavorable stresses, since steel and 
concrete possess almost 1déntical coefficients of expansion; 


2 separation of the two structural materials is thus excluded, 


All suspicions regarding this are regarded as disprovedbp many ae, 
tests by frost ana fire (especially by Boufniceau and Wayss 
& Freytak Go). To Mpetias for teuperature variations expansion 
ae are arranged at distances of 30 to 40 m in buildings € 
(10 to 15 m in the ofen air). (See Fig. 167, also Part II, 7 
to edition, p. 35). The possible extension for a distance of 
15 m between joints and a difference of temperature og 30° Ce 


191 
runs to 15 x 1000 x 0.00001 =x 30 = 4.5 mm. 

Wartemberg Regulations:&-- ne effect of temperature varia- 
tions for structres in tne open air for a difference of By he Ce 
above and below the average temperature of the air is to be . 
considered during the construction. For supporting members of 
more than 70 cm minimum thickness of concrete, the limits of 
variations of temperature may be reduced to + 10° ©. 

according to experiments made, for Portland cément concrete 
the average coefficient of expansion for ay Kan is about 0.0000137; 
tor mila steel it is somewhat less, about 0.0 0000123. ~SWith si 
loss of heat tne concrete thus contracts nore taan the steel, 
With increased temperature the steel extends more taan the con- 
crete, so that -- as in the hardening procedure -- opposea St- 
resses occur in tne two Materials. for: the setting in air acc- 
ordingly a reduction of temperature 1s wore favorable than an 
increase, since in the first case tne colpressile stress in « 
tae concrete can neutralize the tensile stresses produced. By | 
a isc of 1° @C an spans" stress of 0, = xax kk ifBXa = 

200000 x Hed Pie Rel 5 kil/cm?. 

Note 4. Pe ten’ AGGOTGIAS tO experiments. oF. the German Comm— 
Vesston (heft 23) there way be taken 0.000010 OS AN average va- 
\we for the coefficrient of .exv&nsion by de aneea~ See ee ae 
19413, pe. 168. ihe te 

fain rstance of Steel. — 

For reinforced concrete construction almost exclusively cen 
€S into consideration mild steel. In structural menbers under 
flexure tne usual calculations of the strengtn will aepend on 
tne degree of saiety of the stresses 1n the steel. Experiments 


by Scntile have snowa that up to avout 3 p.c. reinforcement for _ 


concrete of good quality, an increasing load produces fracture 
by exceeding tne elastic limit in tae steel, and not by ‘previ- 
ously crushing the concrete, it being assumed tnat sufficient 
resistance against shear exists. The exact knowldege of the 
elastic limit is naturally of tne greatest importance, since 
‘alter exceeding it, the bond resistance: between Concrete and 
Steel suifers greatly in consequence of the great extensions, 
and therefore the formation of cracks is almost unavoidable. 
Hig. 131 shows tne line representing the tensile stress in . 
& steel rod; dat first only very slignt extensions occur 
(elastic Changes in form); extensions and stresses are propor- 
tional according to Hooke’s law.(p.218). Only after passing 


patee 


192 
Only after passing the limits of this proportional relation (a) 
ao the extensions increase wore rapidly than the stresses; th- 
ere already occur small permanent changes in form besides the 
elastic cnanges. Then follows a sharply marked stress limit, 
the so-called elastic limit (b); without an increase of the + 
loading suddenly occur very great changes in form, that produce 
a reduction of stress. Men distinguish between the upper élas- 
tic limit (b), wnere the yielding commenced ana a lower elast- 
ic limit (c), to which tne stress sank after the appearance of 
tne yielding. The stress then gradually increased again, but 
with greater increase in lengtn and reduction of tne section, 
until finally at the greatest possible stress the breaking lin- 
it (dad) is reached. 4 Here is completed the maximnun extension. — 


Finé and invisible cracks in, crease, and the zero line approa- Wee 


coes nearer to the edge under compression. In consequence of 
the strong extensions, tae bond resistance between concrete -« 
ana steel 1s destroyea. But tne limit of the capacity for ex- 
tension ana for the reduction of cross section is first reach- 
ed at (e), where tne break or ropture occurs. 

Note 1.p.219. See Zeits. of Union of German Bngineers. 1914. 
July 2. (Essay of GC. von Bach). AVso see B & 1. ach up va a 
A910. ms £79, 2430994. 


NOte 1epe213.5. On passing. the ehagtie Limit, the rot marks 
e 


Sep a fine | 
VANISH, SMOOTH steel Lecones Babhed, and Network Leth vi- 


HES LS Visible, (the so-called flaw figures). 


According to the Prussian Regulations of i907 the reinfosce- 


mént for tension or compression may be stressed to iG00 kil/em+. 
f 186 

15, 1913, the required resistance, sna be prove | certit 

icate of tests from the Koyal Materials Testing Laboratory ab 

Gross-Lichterfelde, in addition to tne statical calculation. + 


fas required strength and elastic limit for tne different aim | 


ensions of steel au be the following. 


Diaw. am. Area cu* Tens. Strengta. last. lim.ieast. greatest. 


kil/em* 
10 9.7854 4200 2520 2940 
15 1.7067 4138 2483 2897 
ZO 32142 4050 2430 2835 
2) 4.909 3938 2363 2757 
30 7069 3800", 2250 an 2660 
Note 1. pe2%2ZOw. Bhe advantages of the new decree {4200 kV) 


Decree of April 22, 1913). (ACsOreeas to ene yer LbSEST/Sn2 a 


193 
Wust wot ve overestimated, for many rollind WIVs believe thar 
the requirements of auablitay cannot be satisfied without sone- 
Laing wore. ALSO the cost per tonne Of concrete stee\ is not 
without effect. One saves for 1200 instead of 4000 kiV\on? Ve 
deed in steel, but uses more cancrete. (See p. 241). 

Tae extension at breaking must reacn at least 25 p.c. By the 
cola bending test must the clear diameter of the mandrel at = 
toe place of bending equal nalf tne diameter of the rod, with- 
out any cracks. < 

NOV]? 2e 4220. The reoquirement of the cola bending test wild 
MaVe AS A Tesult, that one wild wo \Vonger use Large rods so € 
Qenegvraliye 

The Prussian negulations oi 1904 already allowed a limiting 
value of 1200 kiifes, 1nag¢éeq without Wentioning or prescribing 
special goodness of tne steel. Tne renewal of the old rule fol- 
lowed on the ground of extensive experiments oi the German Con- 
WiSsion aad in reference to tise rules for steel of Jan. 31, i 
i3i0, according to waich for purely steel buiiaings stresses 
ap to i400 and 1600 kil/cm* were allowed. But tae advantages 
of embedding steel in concrete are tne following. 

a. Complete frotection from rust. (See p. 8). 

0. Protecfeé¢gtion against temperature varaations and fire.(p. 8). 

c. Injurious initial. stresses are: Wanting (otherwise bPansb~ 
or ba Ui on and unloading riveted structural members). 

ii Subordinate stresses are far better cared for in veinfor- 
ced concrete construction taan in pure steel construction. + 
ine new regulations correspond to a Zz to 2.5 fold safety of the 
naterial, taking tae elastic limit into consideration. but it 
1s to be consiaerea here, that tae mode of calculation accord— 
ing to the Prussian Kesulations leaas much sooner to an over- 
estimate taan to an underestimate of the actual stresses; for 
toe values obtained by catcucaltion in wost cases are greater 
than the stresses ay ete existing. (Neglect of tensile stre- 
ngétoa of the concrete). : | 

Note 1. Pe 224. SohBe was shown by Wis experiments (EB & B 
AZO, p.332), that already a Viwiting stress of 1000 kil\om* 

Vn steel construction corresponds to a swaller factor of safe- 
Vy than the stress of 1200 Killen VAN VeVvaAforced concrete con- 
structvona The round rods are here stressed axially, while in 
Q stee\ rooft.truss the mnewbers are fastened eccentrically and 


the presence of holes Vs sufficient to double the stresses in 


itn a A 


ASA 
thervyr woricrvnrty obtained for the net section. 

BPurther to be considered ‘As, That WH aV\ structural menbers 
@xposed to shocks, the bive load Vs \\Wncrensed 50 to 100 ReCey 
WRIGHK VS Never required for purely erect Structures, aah Deine ded 
to G@ecree of Jan. 31} 1916). 

Kote 2. ps. Wl, Further see gontrivbs. 1943. .».80, 31, 144. 
LEevtse OF BUnrion of Architects and Engineers, ASLZ. Pe SGe -- 
KRefts 45. to AT of *Gantrivs. on Researches.” 

On tne new rules for quality may be stated thet following. 

breaking extensions of 25 pec. are indeed never reached with 
trade steel. For small steel they are somewhat less, (25 $0227); 
p.¢.) than for larger steel (27 to 30 p.c.). Values lower than 


25 PeCe Should not be recommended in view of the mechanical po 3 
preparation of the steel at the building site (cold bending ee 


hooks, etc.). 


Tac tensile resistance is increased by rolling. with the stem : 


creased diameter. The valués . ‘previously Tound mostly correspond — 
to the establéshed conditions. 2 | ! 

Note BeHe22ie Bxperiments in stuttgart, dave. whe foVvoeing a 
average values. 
Dion. Tens. Res. Blast. ink. Westen 


10 wm 420QkiL\com* 3056 kiv\on? | Reed eye ane Sate 
45 ‘AAA 2856 th 2S BS A ee a a a 


Thus the .eLlastric Limit amounts to boout 2500. to 3000. wWV\ce2, 
According to the “Standard Candirtions for {urnishing Steel St- 
ructares,” for wild. trade steel of 7 to 28 wn diaueter is rege 
wired a tensile resistance of 3700 to 4400. kon? with Oo a str- : 
@tGh Of at Least 20 o.c. : eS - . 

Tne elastic limit must in every case be sufficiently niga, 
in order to nave a suificient safety for the material. in the 


Prussian Regulations tne ratio of the elastic limit to the ten- 


sile resistance for all diameters is fixed at 0.6 and at most | 
oh of the tensile resistance. According to experiments of tne . 
foncrete Union the elastic limit of small rods (7 to 15 mm di- 
ameter)lies nearer the tensile resistance than the elastic wy 
mit of larger rods. It is thus recommended to fix a somewhat — 
“higher elastic limit for tne small rods. (up to 15 as ~ 
NOt]? Le Po 222. According to American experiments on 1260 


vests of steel, prieces., no definite ratio exists betucan.elas- 


tie Vinit and breaking Viwit. Arm, B. 1943. 9.165. 


195 
On furtner regulations for steel, see Table on p. 224, 
_Wortay of consideration are tae Swiss Regulations, taat for 
the case thet tae stress in the steel is reduced to 600 (1000) 
kil/em*, 70 (50) kil/Aem@ compressile stress is allowed in the 
Concrete. (See p. 224). | 
Tne fixing of tae stresses in steel may also be graduated 
according to the shocks to be expected, for example: -- 
1200 kil/ou4 for buildings without vibrations. 
4000 kil/cn¢ for buildings witn moderate vibrations. 
900 kilfen* for street bridges. 
800 
750 kil fom Tor railway bridges. 
& Hlasticity:and Capacity for Extension. 
tae wodulus of elasticity (p. 226) (the ratio of change of 
torm) for compression is ereater, the richer the mixture, the 
less tne addition of water, and tne older tne concrete. Besid- 
es toe modulus of elasticity for compression as well as that 
Tor tension under increasing stresses diminishes, particularly 
for tension (Fig. 122). According to Bacn’s experiments, tne 
modulus of elasticity for compression -- according to the Wag- 
nituae of the stress -- is about 150,000 to 400,000 kil/en* 
rhe: avery high stress. Tne modulus of elasticity for tension ~ 
an uats to about 250,000 to 300,000 kil/em* for the least str-_ 
ess, but then very rapidly diminishes, finally reaching values 
of only 25,000 to 50,000 kil/em*. he ratio of elasticity of _ 
coupressicn to elasticity of tension is ~4 = about 1 to 9 (ins | 
deca = 1 for the smallest stresses, were the same relations ce 
Ex18t as for a perfectly elastic nhaeabae a material). The Aus- 
trian Regulations propose BL = 0.4 #; = 0.4 x ido, 000 = Oe 900, 
kil/em 
fine modulus of cient lenee of mild steel ‘tor Labesudtol as-t¢ 
tor’ tension, ite = a i 000 kil/ien* - Ine Frassiaa ep ekesac oa 


prescribe the ratio i = n= 15. 
Corresponding to 8 488° dus of elasticity for concrete of only 
ete = 143,000 kil/en*, 1 | 


Note 1.909.223. Se SEN BAK OF aoeVeees Les Sia uanes 
ver, G SuStTaNtVaLly Wisner value (avout 300,000 kiv\em*) nay 
be Inserted, since our calculations of the stresses are deriv- 
@& from a conditian of Loading, that ts Vn the vricinirm of fr- 
ACtuTe. H VS naturally no actual Stress, but is only the ewe 


POOWERO SOY —eerUe—oT— tire 


496 

reciprocal value of the extension number a (see p. 228). 

According to experiments of tae German Commission (Heit 25) 
the assumption of no = 15 (corresponaing more to the stage ort 
fracture) appears entirely suitable, and also more favorable 
econowicallyg than n = 10. Tne value i0 nas as a result an in- 
crease of the caigulated value of the stress in tne concrete, 
but a reduction of the stress in the steel, since the zero line 
moves nigner, x thus becomes smaller (see p. 241). The value 
10 requires greater neignt n, and thus a greater weigat of the. 
concrete. “ i hee 

Note 269.223. See B & Be 1904-2... 10%. a cee 

The Swiss Regulations ‘make-n = 20 or = i0, according to whe- 
ther the steel Lies in the tension or copression zone. This nas 
aS @ result, that more steel-is taken than for the assumption 
of n = 15. fhe stresses-obtained witn n = 20 will be smaller 
for the concrete and larger for the steel; ‘Safety is. ‘thereby | 
Sreater. Hxperiments of Scntile nave snown, toat’ steel in com- 


pression 18 not efficient’ to tue aegree formerly assumed, whe- % 


pak re for steel-in compression n is made = 10.5 Mach abn 
: ths 
hatte: established by tiexure tests, that fracvue is pre-— 


ceded by a strong extension of the concrete, tous an- elongation 
of the fibres in tension, 1.0 to 20 times as great as that for _ 
nembers not reinforced; our German experiments: (Baca, Kleinlo- — 
gel ) nave indeed not confirmed tais, but it is well to. assume, — 
that tne steel reinforcement (witn a correct distribution of % 
the rods) somewnat ‘increases the capacity of concrete. for ext- _ 


ension, Be at least delays the appearance of the first. visible 


crack. «. these experiments was sstablisaea less» capacity for 
extension oi tne concrete placed in 4ir,in. comparison pO. thaw. 
placed in water; tne concrete plaged dry showed. cracks ‘in tae ? 
tension zone under smaller stresses. than beams placed web lce 


197 : 
section Vill. Caiculation of Simply reinforced Conc- 
rete Slabs. 

Ii a concrete slab-be supported at both ends and be reinfor- 
cea by steel rods in the tension zone, and then be stressed in 
fiexure by external vertical forces, there occurs a change in 
toe form of tne slab; particles of the mass change their rela- 
tion to each other and are displaced at tne same time. The fi- 
bre layers opposed to the external forges are compressed anda 
tne opposite layers are extended by tensile: stresses. (Fig.i). 
Hrom the extreme layers, in which tensile and compressile str- 
ESS€S possess tacir maximum values, they uniformly diminisna 
toward the interior, until they finally reacn the zero value 
at tne so-callea~zero leae” or“neutral axis? All fibres conti- 
nue parallel to tae longitudinal neutral axis. 

a. Statical Cooperation of the Structural Materials. 
A reinforcement is first omitted, 80 that merely a concrete 
‘ ae of rectangular section comes in Consideration. According 
Navier’s stneory of flexure, all-cross sections, that were 
piane before flexure, also remain plane after the. ‘resulting 
fiexure, Yet the positions of the sectional surfaces with. iter. 
gara to each other are changed, so far as occurs a rotation or 
them about their norizontal gravity axes. -This Navier’s theory 


has been found applicable to construction in concrete ‘by nuue- 


rous Precared) experiments, and simplifies in a high degree + 
the furtner process of calculation. + 

NOG@ 1. Pe 227. By. the application of Kavier?s formula for 
{\exure Wowever, ane obtains smaller compressibe burt dreater 
Vedmsile stresses, than. ASTUBLVY .exisrt. 

" S$eht\e nas Jewonsiroted, that -- particularty - Vn. the, “Censian 
ZONS -- Quite cansideraovle bending ey the. (Cross. Section way 
OSGUr e : 

Hig. «24 shows a portion of toe slab before tne change of £ 
form caused by flexure. N Nis the zero. dine, that atter flex-_ 
ure takes the concave form N’ N’. Toe originally parallel cross 
sections n w and © p take the positions snown in Fig. i24. The 
corresponding lengths s s of the zero line remain equal. 

If a section a.b be wade at any selected place of tne concr- 
ete slab (Fig. i260), tnen for tne restoration of the destroyed 
equilibrium, the internal forces made ineffective at the place 
of tne section must be replaced oy external forces. Tnus below 
the zero line must be applied tensile forces and above the same, 


Sy 

‘198 
are compressile forces. These are termed: reerere stresses and 
are designated by ao. They produce:a change (A) in the lengths. 
of the different fibres, -indeéd shortened in the compression . 
and Lengtaened in: the: tension /zone. The changes in length re= 
ferred. to unity ‘are termed-extensions ‘and are denoted ‘py ¢._ 
for example, if-a teasion fibre has the leagth 1 in.cm in an 
unstressed condition of the slab, it will attain-a Leagth. alin 
ie bending = 1’ = 1 +A® (tension). or Loe A (compression). ‘Phere 
ocours 1a parallel‘ displacement of the end cross: section by. he 
distance -A. The :extension :of © the fipre: is) then:-—=— 


And the stress, if f = cross:section.of the fivre, ‘is:— 


i) oe ; or in general, o- oe. Killen? 


If one desires two. slabs’ ‘@f the: Balle ‘Cross | ‘sections. and equal 
spans, one.of ‘which is made.of steel and. the’ otherof* concrete, 


the stresses in the corresponding : fibres will. be: ‘entirely. cee | 
ferent. Pebween tae extension and the. stress: ‘is. Mae relation: 


(Hooke!s Law):-- € = ao. Pe 
In whieh « is the coefficient of | extension : (= Se : 


pana 


whien denotes for the different ‘materials aifferent irtenajous fi FY 
per unit of length for 1 kil/cm? of stress.: The. converse value Poke 
of this coefficient is the. modulus Of: elasticity. ‘By (see. PAuS » au 


“a 


oO me} 
222) Gim= taus E = > = ve consequently eg > = ew aban 


Nove 1. 9.228. Therefore - = — . Thusxa: concrete beam 6 Gwe |) 


Vong began Sompnose tie. siress of. QO ‘Allon? OVD, be asco a, 


@% by A = -------- =.0.158 cu. , 
for some tabeuc paral: materials, sparticularly. wrduants ‘iron: a 
steel, according to formula (1), extensions and stresses:have 
tae same ratio at all cross sections ‘(see p. 219)¢: thus & PO= 
wains Gonsiant.:For concrete this: “proportion ‘does. not exist. ‘2 ; 
There prevabls: rather the relation: (for. compression) :— 
of | . 


Eee 


ty disoh seobe ane for mw, the soecalied coefficient of change of 
formu is to be ingerted a value from:experience (1.1 to 1.2) for 
tas aifferent wixtures. On the ground of this exponent or law 
of change .of form,"-one way-exhipit the arrangement.of all ex 


p£sa 


* 199 


exteasions and stresses graphically by.a diagram. In Fig. 126 
i © A if the extension curve, indeed a straight line. by Navie- 


o's Law. The two:fidres:f * “and 'f! are distant s and g! ‘frow ihe 


wero line, and reesive the’ extensions e Ss and. a. 
Thea Ve ee | aga 

Note ee es “Lnoveasing 
stress, | “Wades BOVE PAPLaAly in. wensive, than» ‘Compressive | etress. 
(See ip. 223). | 

The Limitation:of the stress. @iagraw. is) bane. bistua: curve ry 
por. The'’stresses. do. mot. follow. the- law of elasticityy: the. 
ucasure of elasticity -is also. Aa fiovent ‘for. tension’ acs that 
for compression. ; ; 

The statical conditions for: irbingévded aonoress) ‘beams - affec- 
ted py flexure may be the following:-- (Pig. 427). | 

Gase-l. Beginning :of the toading. | ‘At: first, ;Participation. of 
concrete on. the tension - ‘side. : The. steel. is. stressed: to: about 
15 x 20 = 300 kil/cm?.:(20 = tensile resistance. of conerete) . 

Case II a. Increased - ‘Loading... ‘The proper. tensile: elasticity 


of the concrete is exhausted: the concrete’ extends ‘in. ‘put. Bie 


snot measure ‘(increased » ‘capacity | for extension ne the reinfore~_ 


‘ement, p. 226). 


Case IIb. further inorease jof yoading. ‘Phe! ‘oapacity. és tae 
concrete for extension ‘is entirely. exhausted. racks: are bee 
ed, Walch extend almost to. AS Zero. Line. 4 The ‘reinforcement 
must gradually receive all tensile stresses. The: “Zero” Line. 280 


moved upwards. 


Case TII.-Maximum allowable: Loading. ‘Finally Socata: fracture, 
indeed -py exceeding. the resistance : ‘to - tension (or. the elastic 


limit, see:p. 218) of. bhe «Pods, » Or the ibn yoke to. arate i. 


ion of the concrete. * 

Note -1. .p. 230. One: ean consetve, the -vuptured ‘concrete. in be 
cut outias ir: ‘PRS. AQBs Dd BiB. 

Note 2. 06230. In - thts case follous. the destruction ar whadle” 
Of Length of beam. + ASsa Yule, wore’ ‘auriakby occurs. the) destruc 
tVon Vn the viobnity of ! the Support, Ladeed » vn shdeteh tac bracgh of 
shear craaks. (See .p. 160. ond Pig. 66°F). 

The Prussian Regulations allow the use of Hooke's law of el- 
asticity, thus the formulas:(i), according to which a. ratio. ex= 
ists bebween extensions and stresses. The ah be jake fr ae 


pe 


pay. 


Pa 


200 ae 
the stress diagram pdecomes a straight: line p'o r', according 
to Wag. 129 a, that changes dkrection at the zero point o: for 
tne difiereace in the) values. of elasticity. for compression and 


tension has as a. result, taat the gevakues do not increase eq- 


ually upward and downward from the gero line, but show differ- 
ent values at corresponding distances. Toe sum of all compres- 
sile stresses is D and acts at. tae centre of gravity of the 
corresponding diagraw : (triangle). bikewize: % = sum of all ten- 
gsile stresses and acts at the entre. OF ‘gravity. of the tension 
dlagram. Since now the new : rectilinear. triangles. & Oo. pl and a 
bo rv! must. have areas equal to the original curvilinear tri- | 
angles,. one obtains for the extreme stresses too great values, 
which however afford a higner degree: of: safety. co any case & 
the assumption of a ‘constantly ‘proportional stress’ diagram | ‘na~ 
kes easier ln an important. degree, the: Taree: ‘process: ‘of Galo- 
ulation. 7 ‘ 19, haat 


The Prussian Regulations further presorive, gua adil ‘onsile 


stresses in reinforced concrete slaos— mast: ‘be. received ‘by the 
reinforcement, so that the. tensile strength of. ‘the concrete ‘re~ 
mains entirely out of consideration. i On. the ‘ground of this. 
reguireweat, the part of. the stress - diagram lying. below. ae 


zero Line is owitted, a> shown. in Fig. 129 Batre Ce) gd 
Il pb in Fig. 127). | | Da Onan sate Sake 


Note: Le .ps231. See. Be 208. eek ‘Sieac Saskia. XU. 
.D. Determination of Position of Zero bine. Bo 
ue 


for the determination of . the. maximum Btresses in-the concrete ig a 
and the steel, it is:first: necessary to. obtain. ‘the exact. loca- uae 


SOF 


tion of the zero bine. (Pig. 129d). ae 
h = total thickness of slap dt om. a opie ae 


a = distance of reinforcement from extreme fipres. in aunnse’ at 


in cu. (Measured frou ‘centre. of. gravity of ‘section of steel). 

a! = (bh —°a) ='effective: depth of slap in em. | 

Xx = distance-to zero bine fro extreme fibre in compression 
in :Gn. eto se AD Hy ae 

O, and Oo, = maximum stresses ian. ‘concrete: and steel, expres 
sed in kil/cm?. : Wiean, 


f, = total actual cross section of steel in om? 


Then tae coupression = tension and:—- 


D = se bo, eta Fer ie apa | 
HOte 2.peBSi-e: ani, concrete Layer a> Cm. Hie serves only +O 


a i 


had 


204 
COver. the TOdS 1684503 A Pprotectian-frow vust, out has ino stat- 
VGA effect. 7 
Pp. 


ompressile and tensile forces must be in’ equilivriun:-- 
Thus D-= Z, aad ~B==xp +0, £5: i : Pris 


According to.tae law of elasticity, the extensions are in ® 
proportion to the distances frow the zero line: ‘(see Pig. 4129. @)i-- 


Sp feex. we. 2 (eS ma BR) gts Me te He ESY 
fy | Ss ib eh OY ea eR xn) é < 
be Be BR Ree ee ee 
Aes: 
no x Hee ee 
is i cae PG HO er 


That is, the stresses - are proportional. to. the distances: from 
the gero Line, if one takes n times bhe compressible stress” jn 


the concrete. (See Fig. 129 b). i a ea ne ae 
ACO . 1 Ma Te Eat Wee te bik 
Prow egaation (2) follows:-- a, = -B-2-- ah 

MN A eg . fy CAM Vea eee 
Substituted in equation (4): SA Oe ee ae) ay 
AO, 2f x Oe BOR ci mee fae Mae A 

--—2.~~ Sere e OLR Le aie ea D e a ee 

Gy, 0 x Ht yx hagas ua cory ; 


This equation serves to. determine. the position of the. arte 


Line. +.if the values bh and a are: expressed » ‘in: om: and oe eo 
cm*, taen for b is to be inserted. 100 cm. The formula: eae uate 
pene the position of the zero line: depends ‘on. the. effective 


depth a’. and: the area.of cross: section. of ‘the: steel, and | that 
the 'gero Line is lower, the greater ‘the reinforcement. «(Sée- 


Table, p.°238). Furthermore, - ‘ib has been established by exper- oe 
inents, that. the’ gero hine moves. ‘upward witha, increasing load. +S 
Worte 1. p.282. To avoid thar: by ervor. the value of —A be: An- 


cluded under the radical, Gtk WOura, be. je verter ; : %o - mehhvarey 
42 b(h - SURES its 
nf. { — he T 42 b(h - a) | sae 


= aN ape-atin alnetes Sta mee ee te acm aot 


P e 


" wn ey Me : ; te ‘ ; ety 
reek Ne et ee le a), %hen 
Y PUREE DSTI 
results the siupber. formula: yx = 8 _ “at + Z/ vee ch e-© ae 


~ 


Ay 


bee 
5 eet 


202 
NOV? 1.).233. Bor exanple a gvapnvcat solutian for ‘for an 
URSYRESTYICAL section 1s cantatned Wn B & B. 1913. p. 859, 
G. Determination of Maximum Stresses in Goncrete and Steel. 
To determine. the waximuu - ‘coupressile stress Op, in the concre- 
be, equate the waximum pending moment .M in Cu kil to the woment 
of the internal : forces thas:-— 


= Dia! - =). = sR x mo (nt - 2%), 


eae. co, = ssa x Le ine? aa , ve 

For the orainary amount of ‘reinforcement, as experiments: hard WO Woe 
shown, 0) will.always be somewhat greater than- bae stress act— ee. 
ually is. Oniy oy very strong reinforcement does the. calculated 
value almost exactly coincide with the actually measured. value. — of 

As for the actual tensile stress occurring | ‘in. the steel, ac- oe 
cording to the preceding statements, one can only calculate. area 
nean stress, since the tensile stress» acting in the ‘concrete 
comes to the aid of the steel, particularly with a weak. reint~— ee 
orcewent. Also the height of the steel section measures 80 dit, 
ile, that one may assume a uniforw stress in tae fibres at tae Ce aes 
different phir ie 


Be i‘ erg “poked een Vly re x i 
= Z2( 4b SNe! Oe co ae = ) 


> 


e a Vane 
RRR Ra Bes kd ka ae ACW) 


“sy ad id tse Wate 
t. (°b 3 


PBF 
iixperiments have shown, that the values for 3g,0nly teas thet 


appearance @f the first Grack “OnWards Become equal. to ‘the actu 
ally weasured values at the crackea ‘CORSE. section: | for the. .con- ee 
crete in an important deyree ‘is engaged din’ econwang: the tens~ Vibe 
ile stress. oe 
Forwakas (6). and (7). represent. notaing. ‘more Sean the. ua 
relation k = M:W out in a different forn (on account of the 
existing steel» reinforcement), 
According +0. the ‘Prussian: ‘Regulations for slaps with less 
than 0.75 p.c. reinforcement, tae allowable stresses in the 
steel are determinative, - and. only with a higher. reinforcement, 
tos allowable stresses in the concrete. (See p. 236). 
On the allowable values of tne stresses, | see ye 205. ‘Ef <a 
fourfold security ve assumed, for o, = 1000 ce » bnen for. 


* Steel reinforcement of :—- 


208 
the allowable compression is:— : ; 


4°) 27} 4° 4 
20) 30;40345,).50)kil/cwg?. (See Table p. 238). 
Calculation of the shear and bond stresses are only required | 
for Paige in the rarest Gases. 


RM ae gS te ates le Pg 9 <7 e 5a s 6 
' ¢ $ 


i,1)3 1 : | 
=,\- eel =|p.c.of concrete cross section in reinforcement. 


-quires a prelininary accurate ‘statement. of tae thickness ‘of = 
‘tae stab. and | ‘of the’ sectional dimensions, ag! well. as the numb= 
‘er of the steel : rods. ‘But in. designing. a slap. the previously 
unknown - magnitudes are brougat ‘into. the calculation: as ‘unknown 
quan bities. ‘The moment. M. of the external. forces. can ‘be -obtain= 
ed with sufficient acouracypy a preliminary estimate. of bho oF ose 
dead load. “quations (8); 6) and « (7). have. ‘the object of calc- 
ulabing. tae stresses. 10 for the- given ‘bending ‘moment, | ‘given op- 
oss section and. dimensions of reinforcement. 

First let the wowent:M and. the stresses: bd and o. be given. 

Brow Forwula (4). follows:—- can, | s 

Wore: ‘Ae Ve 23h. The distance. to. ne : ‘gero. nas ‘unbevards. +o. 
formula: ba) represents. ed fraction. of the. effective | aba pene hy 
VOW V3 Indeed: ‘dependent ion whe extreme. stresses. Soper eaters: cae 


PE Wo, ek he th 


ula pi Ry ae fee ss i 
ek ng (it Ceeearert ), | (8) 
ae toe value x of formula: (3). p pe. substituted in formula. (6), 
then results:—- os a 4 | 


If the value-for x of fopmilta | (8). pe. substituted ‘in. formula 


(7), then results:— KM 
¢ Ie = Se ee 
wee at see 
4 3. 
f, 3 ————————— xf at Ae ne 
a a = 0, : 
s | : an x 
By formula repens ese ft, = ars €12}'. 
| e 


For example, if n = 15, o) = 40 kilfcmand o, = 1000 kil/ow?. 
Toéa according . to formula (8), x = 0.875 hfs. gfe 


204 , 
0.390 Y-. 
Db 


According to formula (9): a! 
According to formula.(10): 0.00298¥ Mp . + 
According to:formula-(i1): f 2x (o = 100 cu). 

(Mis in.cm kil, x, h' and a in cm}. See Table, p. 288. 

Hote 1Lehe23d. ‘Ve? Can also Ve ‘abtatned Veet Ly from. the ‘mou- 


ent MH the -FOVLOWIAS Wanner, -- 


accoraing, %0 formula (7), f, = ES OC CN GA now for the Bx- 
ample; ar on Oe ae - ) de 
AX = =X = -----, ) and | a Vwset 6Sod Pele 3. e taan 
3 9 9.375 7° ‘ Xe 2 Xe ! 


Vikewise resubts:-- {2 = 0.00203, M Des (ot chedom env nein and 

pase a o20un Mee (M wow Ki, dD Aw wed 
Another relation for the value f, , and this time in refere= — 

ence to the thickness of tie slap is found oy formulas (8), (14). : 


Jes + #8 Bp “bp 3, rie : 
f. = Paar eadinad BLN x rat 2, eu | (12) a i 


a tis 


Thus this formula determines the required cross section on 
steel directly from the effective depth h!'. ee ise 
For 0 = 1000 kil/en*, o, = 40 kil/om? and p- = 100 om, taen: 
X =< (ia! ) oF g80 ‘that. ite = 7 al, a > 
44h One CONSE, %Or he. soadiebicen’ ky direct. application: ot {orale 


kid}, 10nd. {ur theraore ~-owhich Vs svupbest -- by. aa nies. 

of formulas» AQ): and: (40); w = 0.390 Vi, Ce a cab ‘es 

yy We Lao ue 

The cross section f, of tge steel thus. stands in. the. See a 

bo the effective depth al: = = 0.750: that bash ‘tne reinforce- — 
ment amounts to Ould pees Bey Rie? ‘effective cross. section, ao eh 

tne section of the steel equals 0.75 p.c. of the ‘rectangle wt: 

with width bo and-height(h —— a). A sualler. percentage of rein- | 

forcement results in a higher tensile. stress in tae steel: for 

example, if for o, = 40 kil/ om? and a, = 1200. ‘kil/ou®, 

at oP 

Fracture then follows in consequence ofsendeba sag ‘the elastic 
limit.of the steel.(See p. 218). Only with a strong reinforce— 
went is the cause of fracture the exceeding of the compressile 
resistance of the concrete. 

If py the aid of Mahi dhe sh for designing a definite neice 


= 0.555 . 


205 
of f, has been found, then a certain diameter of rod is chosen, 
and then tae required number and also the distance between rods 
are found by the Table given. in the Appendix. 

If dimensions of a slab have been obtained, still in check 
Ane (perhaps in consequence of too low a. value assumed for .the 
PAM aa load), too nigh stresses are found, these may ‘be avoided 
in three ways. a Ma 

ies Retaining the thickness of tie slab and ‘increasing f, 

2. Retaining the value of ff. and increasing depth of sabia 

S. Increasing ‘dota : £, and: the thickness ‘OL slap. , 

In all -these cases a A dodaa then -of the stresses” in. the concr- 
ete and the steel is produced, particularly. by increasing tne 4 
taickness a. @onversely, perhaps oy a too favorable assumption 
of tne dead Load, neither of the two. structural | waterials. is. 
stressed to the highest allowable. value, then. for economical 
reasons the dimensions of one. material are reduced up til Lt. Le: 
fully utilized, thus attaining its. highest stress. _ 

The derivation of formulas. for other. Conditions Lot. stresses 
proceeds in the same wanner as before: in ‘the Tables given on. 
p. 238, 239, these values are- collected for different stresses — 
Sg and O).. ( fre Ta Mes See Arpemtir) 204, 2/0.) : 

The Tables can also. be used ‘in tae following manner?—— 

Let the given bending wowent Moe 600. a ‘kik, The slab is. bo 
be 12 cm thick, 1 and. rods witn: +? 2 cn diaweter are to. pe. eup- 


loyed. 0) = 40 kil/ow?, /M = 28.3, and h! = 12 — 1, 7 = 18.5 a | 


The given dimensions - corresgond BO.a: definite value. Ks for ‘Bis 
that is. Found » in the’ Following : ‘manner. pte hae iy 
teh= = Some 2 0,371 . 
K aed F wn 08 8. Bagi 


The nearest ‘value in eye: Table . is. for K as 367, ‘indeed for ea 

= 800, dy = 40 kil/om?. | ! | 

"Then is required ff, = 0.897 iis == il. 24° on? | 

Phus Zor 1 m Widta. ror slab, by Taple of round rods (Appendix) 
pie gle used 10 rods for. reinforcement. if, Srddeee ione. 3 

n dfecial cases ‘interpolations ‘can be ‘made. - Ror. exauple, tp Sg a 
/M = 20, then the process» of caleulation would be. the following. 


K = a = 0.625, thus Ke = about 0.211: x 20. = oe pe ‘Out. 


finally and conversely. peak a given M and given cross. sec tion 
of steei, tne required depth. of slap may be obtained. 
Get M = 4000 mw kil and £, = about 11.30 cm? (10 rods of 1.2 


nt aoe 


206 | . 
Cm diameter. ah ue ia \ ay 


Thos f, = K /M, thus kK vit? 31.6 (= 0.368. ve fi 


The nearggs values in the 7 le (6, = 40 kil/cm?). are cae 
Q,337 for ote and 0. 397 fo for a ‘Then | Ar = avout QO. 375 fl = ally 
hi. 85 Clie ; 

If ais assumed = 2.15 cm, siton h = 14 om. ene el oF 
For a given live load g (including. ‘sudcrindoyuedtorany, tora | 
to save the preliminary estimation of the. dead . load. and . bhe. ale ; “ae ae 
culation of M, Henkel (Zeite. fir Tiefbau, | 1913, p. 106). has ae pot ee: 
established for the usual spans:of slabs the: following dokiye- (au Mo. 
ing formulas. foro = 1000 and 40 kil/cu®, a =< 1.5 cm. | bata 


nl = ee a 14% + 36°, for -M = mh Fe : oe je" a a Si 
4 c ‘ 7 A c i 8 id } i Dy - * 
{* I _ 1? i 


h! = ——— + a 


Jae + 36,2 as Sa he ie eg 
feo * ob Mit ae ee 


| Be OT ow ei Mee 
bis ~== ane g@ + + 36’ ah Ra Ses ee 


8.0 969 _ 1b ! i 
Note 160-240. Accoraine - i mactan ter Aco: Lp. 2h8)y we noua = 
2 cr 
ei9 2.190 7 
as AO Te alee ¥ a0. #66 = 1508 ou,” 
hod re Fadi 


Rg = 097 x 7,02 = B27 om” 6 re, fos 
Further Notes for the ‘use of Taple on p. 238. er . 
With: increasing 9b» An values ‘for if, also disinisn, ‘but on 


ume too ai 7 rosa taupenen ta gince otherwise: tom nigh! uuresee. 
a. vi ak 
es in the dale ni ocour. ‘bikewise otal resistance tien. 


/couw?. On the other ae ee save conerete, pas is. ine. eke Fe 
taing, to obtain a smaller thickness of tae lap, thepeia tile “3. Me 
en for the concrete 40 to 40'kil/om® as. the maximum stress, 3 me ie 
but for the steel only a value of 750 or 800° ‘kil/om?. Tt risi ea NS 
uost economical for slaps to. utilize fe up to. the. permissiple — | ee 5 
limit.-It-is also to be considered, Anebuann values Of Gy be i ee 
coming smaller, the thickness of . the slab is. “reduced very piteis te 
tle, of no importaace in, practice, but on. the other hand, the ml 
required cross section of the steel» papidly pecomes excessive, — 

so that finally bhere is .no economical advantage. (See: ‘Example * 

1). Resulting conclusion:-- one stresses the puilding | wabterial, | 


which 18 to be sucaoni aaa’ “tol the geentpaatee etme ae 


: a 
eo & ee ast 


nD 
1 


bed 
Pp 
ERR or 
3 f} 


207 
other material not to the limit. 

2. The Tabke is based on the official -requirement:of the rae 
tio of elasticity n = 16. For n = 10, one optains a suwaller = 
steel section, dut a considerably thicker. slap. + Consequently 
for the same structural material or member, the stress. Oy bec 
owes greater and the stress Gg smaller, the less the ‘ratio.of 
canes! a avis. * In. the. following ‘is given .a. delleatious8ér. 

= 10 (See Table. on p. 238). 
Note 1.7 ry Cee SCS ope- 2236 
XO] Be DeBhie Bor: exaupis; incsording, to Table on -p. 2388. 


1 ene Tom 


ei ae TA he me ha 
1000 30 25 0.426 4/0.274 6/0.644 p.cd 0.429 bh! 
1000 30 | 15 | 0.490 a|9.228 B/0.465 p.c} 0.810 hh 
4000 30 10° ) 0.559 «|0.194 p]0.347 p.c 0. 281. ae 
2 i . ae r ‘ ee . . eat 
41200 30 01596) 4s 104449. 0.200. 
1200 35 0.523 Ockleny.. Onze. 
1200 40 0646816 06198 ye abe a 
1200 "45 05422-2750 Baeie Oates 
1000 90). 0.860) Opt SO Sau 
1000 35 0.490: 2 ¢ Onedet? 1 205266. 00" 
1000 49.0 304388. 5 OL ABO 9 wea 6 ign 
1000 45 0, 896% 08 590 20R. Co OaR ia 
900 30 0.540 © G.228°  ¥Ou260 
900 40°") 50.626 '\ 04207). 160.308 eRe Rr 
300. 30 0.517 0.264 OQ RB: at CO) Us a 
800 40 0.404 AOuSBA 2h OR BSR Ros wee 


‘AGL, See yD 
Pine waximunm stress: Og of 1000 kil/cm?- (instead - of. +1200) -has 

a smaller depth of | slap, . bub a larger: Seetion: te Ore steel as 

a result. + Por: example:=- i 


0.441 Vii, and £, = 0.228 /il. 


Lt 
i 


Sp 488 | Ay 
Por. ie8 = oem eh! = 0.990 YN, and f, =,0.293 /M. 
i : as 


NOCE 1. Po 2BAZe SLE Ve BAe 
4. For sualler stresses in the steel is inoreased the compr- 
essile resistance to flexure, wherefore also higher limiting 
Values for 6) may oe permitted. Hagesser ‘proposes for. this case 
the bate hs formula. - (Aru. B, 1941. p. 250) ..K— 
= 40(2.5 —- #1i.5 333): “70 kil/om® in the maximua case. 


208 
The steel contained would then pe (for n = 15):—— 


or o, and 0, = 1000 and 40 kil/ow?, 0.75 p.c. 
For 6, and O, = 800 and 82 kil/cm?, 1.60'-psc. 
For G, and G, = 600 and 60 kid/ious,)) (328. Des. 
For O, and d, = 500 and 70 kil/ cm?, 4.73 p.c. 


The formula ee, by Schnble. for the Swiss. Regulations puns: ae 
(see Pp. 220)i—— 
dp = 40 + 0.05 (1200 -- a e) # 70 kilfem? as a. maxima. 
According to this: formula then results. the steel “content (n= 20). 


px NS 


For G, and o, = 1200 and 40° kil/om?, 0.417 pc. } | 
por GO, and oO, = 1000 and 50 kil/om?,. 0,884 pec. Caine ue 
For 0% and o, = 800 and © kil/cm?, ~®.6810 pc. aie 
) = 600 and 70 kil/ou?, 3.126 pic. ee u iT sf 
potting ine 38 Pe 
5 é Finch ist Pigetion.of both: structural materials: aoe rey 


= 0,375 nh’. The’ gero line lies. at ¥8 of. the effective Bear 


pet cada cane! tae: hover ara between tensile and. coppressile-for- at: 


ces =) (Rl — = x) == of the effeotive. depth. -kecording to. for- hs: 
wula (7), . then. the required steel section - for an assumed | slap 
n cm taick with: full> utilization: of. both structural materials: ora 
(Mf an m kil, a! inom). +. eo hed oe e 
= 0.415 = =, »(for = “aa hte = good ae {tor 2s | on 
Note eae THLE « approximate - formule: can. oe) employed. for 
depths of SVG0S © Fvop#fl Sto 12 on, since . WHT, auc yressures tn 


eh 
PR ot 


ERE GONSTEVS :WO | MOTELS ALterations. .QOCUr. We Se, rat 
On-furtherd desired : formulas, etc., See .omong * iekvors,. B & oe 
L907, po2954 1908, po27S, FBZ, 190A, p.W2, 98, 104, 204, 268; ia 
ArwWe Be 19190, Pe 234 “ASLA,» ‘Re 60, - BG, contrive. 1913, /p.486, 1056 
for accurate. calculations then result. stresses, that are. still 
somewhat swaller than the> inserted@ De » 80° that a ‘higher. cree 
ree of safety exists. ae 
According to Koenen” is approximately eich is (44). 


<= a = 4.9 RE TRE 
1000 4% 9 - vou 

7. Tae covering Layer. a must be so chosen, that. between. the 
cottom of toe steel .and the surface.of. the conorete exists an. 
interval of 1 to 2-om (Fig. 180). For example, for: ‘rods of 10 
wn Giameter, then one aut bake for a at least 1. 5 cm. be dara 


yoy 


209 : | 
P P38 r (Zoruula.9) ‘ t (formula.i0) 
Bifective neignt a’ = ra Steel section f, = t B 
woment Min m kils.width of slab b in mw. 


For slaos:—- { ao = /M, 8 = /M. 
Por beams and T-beams ; a = ‘i, 6 = ‘Mb. 

Gy + Gig = 1000. o, = 1200 |. o, = 1060| 6, = 1200] . 
20 0.686 a 0.782 4° 1, @ 6189 -p.\ er eguee sg i 
21 0.659 o 0.702 a... 0.166 6 |, 0.127 § 

22 0.682 a 0.675 a Q.1739 B72 064848. 

23 0.610% 0.6494 0.180 8 0.468 6 

24 0.588 a 0.628 « 0.187 6 0.144 8 

25 568 a 0.604 o 0.194 6 0.149 8 

26 0.550 a 0.588 a 0.200. 8 0.156 8 
27 0.554 « 0.567 0.207 6 0.160 8 
28 0.5484. 0.552 « Oy244 8 066 8 
29 Q4504,a ) 0,684) a: Bee Be CO kL 8 

0) 0.490'a 90.519 a 0.228 8 0.277. 6 

ji 0.477 a 0.505 o @p225:8  sQe182 8 

32 0.464 0.491 « 0.242 8 0.187 6 

33 0.453 a O.470' a >>, )oaRds OB 1044938 41) 
34 0.443 « 0.4670)! i, O.254,8.° O,196 B * 
35 O:4a8?e. 940 4b7 0. NORGE RB ,  -Oheoe pe: 
36 0.423 « 0.447 4 10.2678 05208 8, 
37 0.444 « 0.438 a ‘OasTs Bx : nos 
38 0.406% 0.428 4 9.280 8 0.228 sR 4a” 
39 0.308 a 0.419 a 0,387 6. 
40 0.3000 | JOsits. 0.298 6°) 0.8286 
44 0.883% 0.4080 0.2006 | 

42 0.8760. O,8G@ aie  OLG06.8 i Guzse Br 
43 0.3870'0  Os88B me 4% . 0.310, 8 0.243 § 
aa 0.363 « 0.a08e SH . O.817-P.) O.Bed 1B 

46 0.351 0.3684 °° 0.380 8 0.258 B 

48 0.840.0'. WOsaS iy i es 0.3416" "Ou 2ee.B 

60 0.380 a 0.345 a @.854.8 “O77 8 
60 0.280 «.. 02801. q. ‘Ott gs OlRBS 8 

70 0.2694 0.269 4 | 0,465 B 0.866 8 


pamen ones 


O2ss ae ee 


210 


PR89 Steel section f, ‘ s (forwula 8). 
OPT Hee a i Distance to zero line x. 
(See formula 12,p.236). x and h! in cum. 

Oy Gg = 1900 o, = 1200 4 = 1006 cP 1200 
20 0.232 psc.’ 0.167 pce 5 0.230." 0.200 a! 
21 0.251 p.c. 0.182 p.c. 0.239 h! 0.208 a! 
22 0.273 p.e. 0.198 p.o. 0248 1h! 0.216 h! 
23 pode) pies 70.2138 pies Ol eb? a 0.223 a! 
24 0.318 pie. 0.220 de. sO NCO ha! 0.231 a! 
25 O.341.pec. 0.247 pec. 04273 1! 0.233 a! 
26 0.964) Bieun? 0.865 0.68. 0.280 Be 0.245 a! 
27 0.389 p.c6. 0.282 p.c. 02288 1? 0.252 a! 
28 0.414 p.c. 0.301 “p.0 14205296). 01 0.259 1h! 
39 01440 pio)! 0.820 pies? Ogs0sin! 0.266 a! 
30 0.465 pic.) 07841 pec (01880 (Ht 0.273 a! 
31 0.498 pid. 013860 7.6.5 0.318 mi Of27o nt 
32 0,620 p.@4..0 CO. 881! pe. (0 eaacn* 0.286 no! 
33 0,648 pies 10.403 p.c.. 0.3810! 0.292 i! 
: 0.575: pve. .10.425 pre, 02328 bh! 0.299 hb! 
35 0.603 p.c. - 0.445 p.c. 0.3442! 0.304 A! 
36 0.682 pec.’ 0.466 pic.) O.SG2 ih! 0.310 on! 
37 0.661 p.c. 0.487 pec. 0.857 h! 0.316 h! 
83 0.690 psc. 0.509 p.c. 0.863 a! 0.322 a! 
39 0.720 pec. 0.582 pio. 0.869 hb? 0.328 i! 
40 0.950 pec. 0.555 pecs 0.370 B! .. 02833 -h! 
41 0.781 p.c. 0.578 pec. 0.381 i? 0.338 hh! 
42 0.818 p.c. 0.601 p.c. 0.887 a! > 0.944 AT 
43 0.838: p.¢s 0.628 puea  Oseve a 0.350 on! 
44 0.874 pec. 0.649 pio. 0.398 bh! 0.855! 
48 0.940 psos 0.699 p.c) 0.408-h! 0.365 hb! 
48 1.000 p.c. O.751 pic. 02418 5h! 0.375 h! 
50 1022.-pics O.808%516..0 04420 i? 0.335 al 
60 1.423 pec. @.073 psc. 0.474 h! 0.429 h! 


eli 


ae og, =.1100 kil/em? ve dei 900 kighae® oh 0 
SD i t ) r SpA: Ss 
300.504 a] 0.199 6 | 0.290 b'/ 0.474 a/ 0.264 B| 0.335 a! 
35 0.465 «| 0.229 8 | 0.387 AG 0.420 4 | 0.301 8 | 0.868 hb’. 
40 0.400 a | 0.258 8 | 0.358 h!| oe & a | 0.337 8/ 0.400 a! 
45 0.366 a| 0.285 8 | 0.380 1 nt} 8 3:34 | 0.873 8 | 0.429 h!. 
80 0.859 0.311 6! 0.405 b'| 0.322 a| 0.407 6! 0.455 a! 

q. o, = 800 kil/cn? 3, = 750 kil/cu? 


S 

a 0.451 a4 | 0.888 6) 0.375 a! 
0.408 a] 0.353 8 | 0.396 b'| 0.401 a | 0.885 8| 0.412 hb! 

a | 0.397 6 | 0.429 h'] 0.363 « | 0.480 6 | 0.444 al. 

« |0.436 8 | 0.458 hn! | 0.334 a{ 0. 474.6) 0.474 b! 

9 


50 0.814 a °0.475 8 | 0.484 b' \ 0.310 a) 0.517 B (0.500 bt 


0.26 omlated 
Using a flat par 80 x 6 mm set on edge, the distance a snould 
ope at least 1.0 + 1. 5 = 2.5 cm, or better 5.0 cu. ) ! 

Reinforced concrete slaps are almost exclusively made only 
in taicnesses of entbre centimetersf; depths: of floors of 8.5 — 
or 10.5 cu, Clee, are disadvantageous in practice. For example, — 
if h' is some Ze 2 cu, ana one desires. to use 3 uu steel rates 
vnen must a pe made 1.8 cm in order to optain o in entire Cs... 
But here ty! com would already practically. suffice bor a, and 
one would do best to retain this value for a and to increase ‘ 
nt to 7.6 cm#-for it is not impossible, that with the consider 
able effective depth of 7.6 om, some saving can be made in the 
steel. 
RAG prevent formation of cracks on the underside of the slab, 
the depth of the ESASLE RS covering layer is made thicker, tne 
greater the Giameter of the steel rods. For stiff shapes (I-3 
beams) 2 to 3 cw are always to be allowed for thés layer. 

3. In simple buildings a thickness of floors from 11 to 12 
on = regarded from the standpoint of economy -- are to be con- 
sidered maximum. values. Ifa greater thickness is necessary, 
tacn is generally to be. recommended an arrangement of the floor 
in slabs and- Tebeams. ie 
On tae consideration of negative panel ‘moments, gee Bxample 
S, and on the consideration ef negative nomen tS at the supports, 
see Hxample So. ; Wee Gen hot 

9. for the steel section f, , too few rods should oe ta= 
keg, since the distance between the rods would then decome too 


i 


212 

great. Por example, if f, = 2 cm*, it would be an error to take 
4 roads of 8 mm diameterd for that would give distances of 25 cm. 
In this case should be taken about 8 rods of 8 mm dlaneter, ever 
if then tae actual f, be Substantially greater taan calculated 
as necessary. As a maximum value for the distance of fine rods 
apart way generally be taken about 2(h =—- a): but thgn there 
must oe distributing rods in sufficient number. In smaller th- 
icknesses of floors (8 to 10 cm), one should not go peyond dis— 
tances of 12 to 15 Cm, and indeed wita daansters at least & mm, 
Too swall rods bend in concreting, and are hard to place on a 
account of their flexibility. | vgs 

40. Much saving of labor and time may be caused by the use 
of suitable books of Tables, that are particularly to be used 
for designing slaps. and supports, Certainly these Tables are es 


in part estaplisned without regard to tae resistance bo shear. 


and pond, and way sometimes: afford opportunity. to Hira unskill— 
ea to select uneconomical sections. 

For all calculations is. recommended tne use of the spies poke 
Also most of the #xamples in this book may pe solved by the s oy 
sliae rule. tu . PN 

Let tne problem be given, to obtain the waximum possinle live 
loaad for a concrete slab without : reinforcement, i m span and aks 


10 cm taick. 


ak ~Q x 100. 100 x. 10? » 
Ata Lution:—- w= Wo , tous 5 Ss Sec: a ES O- 


(4.0 kil/cm? = allowable tensile stress in wonhor, witnout. rein~ 
forcement). 


Q = 538 Fer 
Deauct dead load, a 1 «x 2200 —=629_kil 
Remains for live load per m* ~ | Recs 3i3 kil 


Note Le pe2hd~- The scapes rentistate Vs goout 10 times 
as great, but naturally cannot ke used Neve. © i 
Koenen takes ato account: the “Gi ference Vetween. tensive | and 


compressible elasticity and mioenen the ees 5 forgulosi-- 


Sy Mews O eet til Yh) Me oy Rn oboe hale 


“Tensile stress: 6, = 0.95 a | 

(Koenen, Ground ‘Pprincvprles of Statical Galeulation of Goncre- 
te and Reinforced Concrete Structures. A th editrvon.e. WeBrast . 

flor the use of rolled shapes safe against pending, the proces 

cess of calculation is the following. (Also see Section X.p. 269). 

1. @btaining the distance x to zero line by formula (5). 


213 
2. Obtaining tae compressile stress in the conorete. 


goes AMG 
b x3 Ma i i te 
bin rat n{ I, +f, (h - a =x)?] 


3. Obtaining the tensile stress in the steel. 

GO, = : =n ns a rn Cb petro i 

‘ x 
Here [ = moment:of inertia of the statically effective sec t- 
ion about the gero line. 3 : 
Wa = moment of resistance - referred to the! ‘coupression 

edge of cross section, 
W, = moment of resistance referred to. the tension. edge: ne 


Z 
of cross section. 


(h, - x). = distance of tension edge of steel from the x axis. 


PAY® Bxamphe ie (Figs. 1382, 133). | | 
A freely suppovted slab is to be designed for a clear span 
of 2.0 m. five load of 300 kil, flooring 90 kil/u?. | 
a. Maximum possible utilization (ai bota pibige ee kes waters 
ials. (40 and 1000 kil/cm?). ‘ ma 
Thickness of slap. assumed at 10 cm: “then distance Galdeen s ie 
supports = 2.0 + 0.10 = 2.1 My and dead bah hot of slab = aon Vi 
x 2400 = 240 kil/m?, aes 
Total Loading «(G00 + 90 + 240) x 2.€= 1828 kil. so 
Note 1. pe®hS. Striortry speaking, the NAge: voad As. onby. he! . 
be taken for a Length of 2.0 w s e\ear span). 
M = i= 2 aaa eat + 347m kil: W186.” 
ee = 0.298 * 18.6 = 5.46 cm? = 11 rods of 8 mu, (f, Ei. ont). 
n't =0Q, 390 x 18.6 = 7.26 om: bh = Q Cll. } 
Since the moment M is assumed too large (h was. estimated at 
10 cm), and then also for rods of 8 i diameter, Bee oF ah 
= 7.6 cm would suffice, this makes necessary the following re- 
calculation. : 


eM t 


1 = 2.0 + 0.09 = 2.09 a. 
& = 0.09 x 2400 = 216 kil/m?, ee 
Q@ = (800 + 90 + 216) x 2.09 = 12867 kil. 
y = 200 88 a sl As ee, 
. ? h! Tie 
P j ‘eit. 31° pk ‘ s = « = — = 4 as 
According to the statements on p. 237, K Ti 1803 0.41 


iY tunct 


o14 
to this value corresponds, found by interpolation, for f,, K = 
a 272 (witn stresses of 1000 and about 36.6 kil/cm?. 
= 0.272 x 18.2 = 4.95 cm* = 10 rods gf | 8 mu (f, = 5,03 om? s" 
(According to formula 13 f, = 0.115 —— = 5.0 aie | 
Gontrary to tae first calculation i rod $f 8 mm Gan be saved 
per lineal m of width. As a check may be computed the Limiting 
stresses 0, and dg . | 
Note WepeAhG. Lf the work be Gone by the Raves. the checking 
of stresses Vater by formulas (6) and. (7) Vs also generally no 
Vanger necessary for the officials. : Beis Sie 
These way be more quickly obtained by the Table on p. 239 for 
3) = 36.6 kil/om*, x = 0,355 x 7.6 = 2.70 cu. 


2 x 33,100 
sn) gt cee ct compe eae neha RED: 19 2. 
OD TOO k 2.7L he Oe 86-5 kil/ow 
33.40 
Bis GR Saas EES 88 kil/ou®. 


5103 «(7.6 = 0.5) she 
The crusaing resistance of the A according to the ele 
ussian Regulations must amount to 6 x 36.5 = 219.0 kil/cm?. | 
Toe stress 6, In tne steel therefore becomes Less than ae 
kil/em?, since the existing steel section (6.03. om?) is larger 
that’ that required (4.95 cm?). For tae same reason tae stress 
Oo, is also a little smaller: for oe ake line is somewnat Lo- : 
wer. ae ! 7 a8 
o. Toe slab is to be only 3 cm ‘thick. 
According to what was stated on p. 240, a substantially sir- | 
onger reinforcement becomes necessary. ae 
1 = 2.0.+ 0208 = 2.08 li. 


(g = 0,08 ® 2400 = 192 kil/m?. 
Q° =. (600 (F590; + 192) x2. 0&8 = 1210 kil. 
pe eee eee ee kies Ve, rd 
For steel rods 8 mm diameter a! = 6.6 cm: K = coe = 372. 
For stresses of about 800 and about 39 kil/om? ; f, = about 
0.300 x 17.74 = 6.90 cm® = i4 rods of 8 mm,(f, = 7.04 om? 


A reduction of tne thickness: of tne slab py only one cm res 
ults in a substantial increase of tke steel reinforcement, and 
tnus an increased cost of the floor; the steel is not fully uw 
utilizead in it. 

c. The slab is to be 11 cm thick. 

According to the statement on p. 240, a somewhat smaller re- 

iniorgement will be necessary. 


215 


DLE 1} = 2.41 wz g = 0.11 x 2400 = 264 kil m?, 
| = (300 + 90 + 264) x 2,11 = 1380 kil. 
1380 x 2.11 
= s—as== = 364 uw kil: /M = 19.08. 
| | .6 
for steel rods of 8 mm diameter, a' = 9.6 ca, K * ihe = 0.508. 
For stresses of 1000 and 29 kil/cm?, f, = 0.221 x 19.03 = oti 
cm? = 9 rods of 8 um diameter. (f, = 4. 53 cm?), 


Making tne slap thicker has only made possible a very small 
reduction of the required section of the steel: the concrete 
furthermore is not,fully utilized. | es | 

Pinal results of the investigation. (Fig. 133). 
: oa he Sy « Depth. . Reinforcement. | 

a 1000 387 kil/om? 9 om 10 rods of 8 wm, f£, = 5.03 om?, 

> 800 89 kil/om? 8 cm 14 rods of 8 mu, f, = 7.04 om, 

¢ 1000 29 mil/cm* 11 cum 9 rods of 8 om, f, = 4.53 om? 

The most economical solution then occurs when steel and con- | 
crete are stressed as nearly as possible to the allowable ee 
its. If one desires to reduce. tae. stress” Tg in the steel, then 
the reinforcement of tne slab is increased: if he wishes to & ~ 
reduce the stress 0, in the concrete, then the. pRECKR GS & of = 
the slab IS increased. NG Bi 

Example 2. (Pig. 134). Teean ip aie tp Oa 

The positive maximum moment of a floor panel amoral to 324 
m kil. pesides,the occurrence of a negative noment Min thee 
panel of 100 m kil is to be taken into. account ‘in the calcula 
tion(See p. 182, Figs. 87 to 90). Allowable limiting stresses — 
are 1200 and 40 kil/cm?. The compressile, souetimes coming into 
consideration is nere neglected —- to raise the degree of saf-_ 
ety and to simplify the calculation. (Section IX). | 

a. Thickness of slap is determined by the positive panel 
moment. (¥M = 18.0). . | | : 
h' = 0.441 -* 18.0 = 7.4 cm: bh = 7.4 41.6 = 9.0 om, 
f, = 0.228 x 18.0 = 4.1 om? = 9 rods of 8 um, (Fe = 4.55 om*). 
249 », Obtaining the. reinforcement for the negative Bane? hO= 


ment. (7M = 10 1) o 
Thickness of slap ‘must remain 9 cm. Det a be here made = 
cu, then bh! = 7 Ome 
ryan) ae ae oome 
f. = O2127e* 10-2 y om? = 3 rods of & wu, es ee 51 cm?) . 


216 
Example 3. (Fig. 135). 

The negative woment at the support of a continuous slab 9 om 
thick may be 900 um kil. How much steel is to be placed in the 
upper tension zone? Allowable Limiting stresses 1200 and 40. 
kil/om?. f 

a. Pepta of arch amounts to i4 om in Pig. 186 a. 
f, is to pe found for a given Bs %, 
hi = 14: 2212.0 cm, fM = 50. Pie 
ee eoaady Vlog \ 
Por o = 1100 and 40 kil/cm?, 
= 0,258 x 30 = 7.74 cm? = 16 rods of 8 um, (8.05 cm?) . 
pb. With regard to the reinforcement at the middle of the 
panel, only 12 rods of 8 mm are to be taken for the reinforce- 
ment at the support. ‘ 
The height his to be found st 8h a given f,. 
i, = 6.04 om?, /M = 30, K = = 0.201. | 
ior o = 1200 and 34.6 cil cn? (estimated oy (tacoohac (eae 
Bes about 0.460 « 30 = is. 8 cm; hs 13. Ste, Be a 16 Clit. 

450 | Exauple Be tat aS 

A freely supported slab with he 4 Cul eat span and 43 cm  thic- 
knéss is reinforced by 10 rods of 12 mm diameter: (f, = 11. 3 cu). 
affective depta a! = 11.2 cm. How much live load may. the slab 
carry, if the maximum stresses amount to = 35 and 1000 kil/ow?? i 

Bikey Dera YS WEN: a 

= 1.695, thus x= 1.695 (-- 1 + 1 + w= ri, = 4,68 om. 
b ay 4.698 


PS Wty es thug we = 79.5 
According to formula (6), 36 ERAT » thus MY = 79,280 


© 


ho D = aaa, eich = 108,932 
Cu kil. 
| Naturally only the sma}ier venue eh Naan be taken. 
Moment = a x 100 = 79,280 cm kil. 
9, 280 xB | 
q = oo « weet = 991 kil/m?. 
‘Example: 5. (Figs. 136,:137). | 
A doorway 3.0 w in clear width is to be spanned by a reinfor- 
ced beam. Width of beam = thickness of wall = 38 cu. For prac 
tical reasons the heigat must not exceed 60 ch. The load coming 
on the beam is uniformly distriputed, and amounts in all to 
16,000 kil. Allowable stresses o are 14000 and 40 kil/om?. 


1. Optaining the steel section for beam 60 cm high. 


pee 
Aad ap 


i> 


217 
Span for calculation = 3.4 m, 
Bead weight = 3.4 x 0.6 x 0.388 x 2400 = 1,860 kil. 


Weight of wall OB = 46,000 owe 
Total Load a Ny 17,860. kil. 
: i ° 
Mamlnun moment = see = 7, 590 A kil, 
p R57 


JU = 87.2: sb = 0.38 = 0.616: = = 142. 


M 5 
' =.: : — = i = wee ° ac y 
h' = K de 56 om, thus K = 575 = 0 3e4 | 
For o' = 1000 and 39.5 kil/ou?, 


f. = avout 0.29 /M b = about 0.29 = 87.2 x 0.616 = 16. 88 Bont, es 
5 rods of 20 mm, (£6 = 15.7 cw?). nee 


cn 16 x hee 7 Wee 26 38 x ee aS 20. H ee 
| ae : 16 * 16.7 mi Oe i ie 


2 x 759. og. | PBDLOQO Fee ae he 
A EE ICU Coy wet eee A a “Erte 980 an: 


kil/cm?, 
2. Obtaining steel section for beam ‘oaly: 56 cH Uagh! | : 
Tt is evident that a considerably stronger reinforcement will 3 
oe necessary: therefore . the distance ie should. not be assumed 
too suall, and the. sheight. ht not too great. Tacs . 
bl = 66985 = 61 cw. 


Tne reduction of the dead. load is. unimportant: thus again” 


faa 102. 
a°) 


ks ode = 0.352. 
For o = 800 and about 41 kil/om?, — Ret knee 

f. = about 0.400 * 87.2 x 0.616 = 21.8 cm? = 7 rods. of 2 Mm 5 
(f, = 22 com®). : | 

To kegerte.se the shears are arranged stirrups adcording te Rigs 
1386. Tae aaa Gp = about 41 kil/em?, py tne ‘insertion of me 
some compression rods (about 2 rods of 20 um, that at the same 
time serve, (see Fig. 137) as. aiding rods, Gan pe. ‘reduced to. the © 
limit of 40 kil/cm?. 1 Otherwise ‘it is to: pe. considered that: 
Loe peam ‘is calculated as freely supported, but actually a cer 
kajn degree of fixing exists, and already by the adoption of 
“Sr the limiting stress of 40 kil/en? is reached. In the wor 
st case must one contorm to a further increase of the reinfor- 
cement, which. naturally results in a further reduction of stress. 
tor example, if instead of the two rods in the compression Zone, 


c—~etdi-biorel—rede—are 


ais 


of 20 um = 23.28 om*) . 


a ‘ ¥59 000° 
iad RE RE a dale Nek 


830 x fx 50 


onal rods are Palaces in the tension zone, (thus yk 


sea x = 24.5 oh Ped = 38 } kil/on® and Oe Me 626 kil/cm?, 


> required reduction of the height of the peam by only 4 
mu 60 to 56 cm) results in a considerable increase aa 
st in consequence - the use of more steel, 


id 


nN arn 
; Kets 


+?) hi 


219 
Section IX. Calculation of doubly reinforced goncrete 
Slabs. 
Doubly reinforced concrete slabs will first be employed with 
advantage, when one must consider the alternating occurrence 
of positive and negative momenst, for example for division ne of 
WE reservoirs and elevators (see art ead for ht hel 


hig Mees 1p 


eS ae eae wert 


loads. eee, Figs. 87, 89). ‘In such cages, for a positive bend= 
ing woment, the. teasile stress affects the lower reinforcements; 
for negative bending women ts the upper rods. Reinforcement. for 
compression in general is then only suitable and economical, | 
woen with complete utilization of the compressile stress in &. 
ine Goncrete, toe tensile reinforcement itself cannot be fully 
ressed. The sualler the stress in the tension rods, the wore 
eaveu ase tne insertion of compression rods. As experinents * 
have shown, these also allow # waterial ‘increase Of: the break= 
ing load, reduce tne shor tening in the compression gone, and 
also likewise tae deflection of the beam. As a Limiting value 
for the economy of a compression reinforcement may pe assumed. 
a tension reinforcement of about 0.5 to O.6.p.¢..0f the.total 
cross section. With a smaller tension feinforcement, the doub— is 
le reinforcement offers no special advantage. i! i 

NOC? ZoeHeBD2Zo Bxperiments on reinforced concrete beans by 
the Stuttaart Warterrtals Testing Laboratory (Sontrivs. on Re-. 
search ork iw the Dowain of Engineering. heft. 20, 21) have 
further saown, that the Increase in the > breaking \oad appears. 
to be Gependent upon the &Vmensions OF the veinforcenent and 
On Vis properties (trade von, steels). The StVErups rewatn wi- 
Laourt apparent af \uence on the Wognitude of the waxiwunm Load, 

Doubledg reinforcement will toen also be employed with advan- 
tage , 1f tne slaps or beams extending over several supports 
and with uniform depth have to receive negative moments at the 
Supports. For the calculations here only the width b,of the = 
beam comes into consideration. (Fig. 138). 

Note 100 o253. With the requirement of a very Limited struct-. 
“ral Wevent, a spiral veinforcement BASS be Besar ees, as the w 
MOst effective weans for peductad the even of the beam. See 
Section “VILL. 

Rut the useful effect of the compression ee om for. . 
thick slaps is so unimportant, that the stresses in the doubly 
ceinforced slap differ very little from the stresses in the 


RGM TE OPO 


220 

singly reinforced slab, it being assumed, that the reinforcen- 
ent in tae tension gones are ‘similar to each other in size and 
location. for example, if. one wakes the total compression rein- 
forcement £4 equal to tae tension reinforcement f,, then the 
distance x te the zero line is reduced a little, ba therefore 
the maximum stress 0, in the concrete is somewhat reduced. As 
for tae stresses in the steel, these will not be substantially 
different from those in the singly reinforced slab, while the 


existing maximum stress in the compressed rods eventually does 


not reach tee maximum allowable value = i000 kil/cm?. 

All this is true of slabs of considerable thickness. But if 
a limited depth is required, then a double reinforcement in « 
such cases may be economically more advantageous. A single re- 
inforcement then resulis frequently in overstressing the con- 
p etete: but by compression reinforcement: the stress may again 
be brought to the. allowable limit. As a disadvan tage opposed | 
to the econowical advantage. of a sualler thickness of the slab 


is always an important ‘increased use of steel, and taus a nigh- 


er cost.e-- According to Fig. 139, the compression reinforcewent 


ani 
6 


a. CPA) eggare gol wereld 


Se ee as 


constant M and constant maximum i Sea 


Tae question of compression reinforcement also plays ped 


part in beam bridges with sunken railway (Pig. 140): here is 
first concerned a reduction of the depth of the girder. a See 
Kersten, Beam Bridges. 3 rd edition. $ect. B. 

NOVS? LePe-2Zd4- ALSO Bee Note ann. 253... 

Compression and tension rods in all cases may be connected 
by stirrups in order fe prevent buckling of the compression 
rods. © (See Pig. 144 pb bon p. 363, also Fig. 187). With slabs 
of sufficient thickness. it is to be finally considered, ‘whe th- 
er it be not preferable, instead of compression ‘rods to try a 
corresponding increase of the tension reinforcement. ‘Tae gero 
line woves downward, and the stress Se in the steel thus dim 
py pbishes considerably. 3 Since then experiments have shown that 
"also the compressile resistance of the concrete in flexure in- 
creases with the percentage of tae tension reinforcement, the 
increase of this tension reinforcement would be able to prese- 
it a considerable increase of safety in a given case. 


inereases gradually, beginning at zero, until it exceeds the 
Bin ie of the bye barcoms ibee yg % famepned the. ‘magnitude ee 


ame 


ool 

Note Be Pe 24. TaVS Vs true partrcurlarly for deep Roane, with 
suavLer OTe oath, wWhene the percentage of compression reinforce- 
Bent must be an uportant ane. 

Note 3. .p pe2d4. NBrach (Reinforced Gancrete construction) fi- 
nas for hw = 30 cm, a = a? = 3 om. 

ves ve ob Ce es 

1. Simsle vetwr{t 865 |----| 4605 | 1040 a gah a A 
2. Double 754 28.5 \0.5 \30.7 | 894 \ 431 «4, 
3 SVMgbe yy 2865 ~ 965 --—jh.3 | 695 ([---- 5, 
| Gase 3 in comparison. ce case 2. shous ielwaak. the sane reduct- 


von of Gp, burt. this Vs a subatantiabby wore Vuportant veducti- | 
on of G4, and Thus | O greater - Gegree Of SeCurity. 

angesser shows (Arm. B.} 1911, p.250), that a single rotator 
cement, thee! the Coan idera tion of the stress in cy concrete 
oraole than the douplea Holatiutiaal Meatacaseoceee and that 
the sluply reinforced section increases in resistance in tine, 
since its weakest place, tae extreme fibres of the concrete, 
substantially increases in strengtn by age. On the cong trary 3 
with double reinforcement, the resistance of tne cross section 
primarily depends on the tensile resistance of tne steel, whi- 
ch does not increase with ase. ) 

®#xperiments of Schitile have likewise shown, that the reinfor 
cement py additional ‘steel is much more suitable in the form 
of tension steel, than of compression steel. Therefore the Su- 
iss Regulations also permit —- if the reduction of stress in 
tne steel be Gaused py increasing the tension steel ~- 50 much 
Lae greater compression in the concrete, tae sualler tae stress 
actually in the steel. If Oo, = 600 kil/em, (i. €. wita about 4 
0.¢. reinforcement), then way Gp be taken at 70 kil/om?. (See 
p. 201). Also according to the Swiss Regulations, tne section 
of the compression steel may pe calculated only with n = 10, 

Fig. 141 shows tne construction of the doubly reinforced 
wall of an elevator bin. | 
,»~lne Calculation of a doubly reinforcea concrete slap is per- 
teoene in like manner,as tne calculation of a slab with singly 
arranged reinforcement. Tne distribution of tae stresses 1s & 
evident from Fig. 142. , 

Besides the notation given on p. 231 previously:—- 
a and a! = distances in cm from gravity axes of steel to ten- 


ston and compression surfaces. 


eee 
f and £' = total cross sections in cm? of steel rods in ten- 


sion and compression respectively. 
o¥ and of = corresponding stresses in steel in kil/cn?. 


Determination of location of ‘zero line. 
fhe process of calculation for obtaining the distance. ‘X Cor— 
responds to the investigation On De 231, 


b Oo) x 
Dy = £6 Oh 2 De: erate ts) 2 = Gy fer. 
: ‘ : ce . : bG 4 
Dy + 5, x Zo nence fs G6 x 3 car Sad = O54 Poe 


further for reasons already es. 


fp $ && = x2 (h' — x), and ep : ef = x(x - a ), 
<2 et yaa op t act MH lata I a 
DN ibe: 3 Oe Bo Bg & 3a! 
Byes ey Rie Mae 
Ey val On bt > ae. 
Be = Sh S - x) 2 and 0} Ut te atx ~ af) - 
Renae . 


If these values found for 0% and of be deh sabato ‘in the € 
Jeneral equation, D, + B, = Z, there Fesul ts: —— 


yD a op ay le = 8h uhtee a) 
Srna 2 IPE 
bp. £59 Par 
o, xb G, n a ee i Bee ; 
sca 5 Ai [pty Aah a Wik pe ai & 
x* °° b S02 al f, en Se Eg at] 
x? + 5 (f+ fh) = ee b's et fq 


“Ror the simply reinforced Oe! O, and. ‘by: substituting 
‘his value in the preceding equation, one obtains the formula 
previously deduced, ‘(p. 232. Formula 5). : 
Sant Cima re 
x? 4 =-<-=8 x = rae ao’. (In the Prussian Regu- 


lations ais placed = a!). . 
Determination of maximum compressile siwede ‘in concrete. 


Again equate the maximum bending moment to the moment of the 


internal forces. " 
M = Do (hb! ars eit Ds (at wired at). (16). 


223 


M = au (ht - rs aii +E fie (a! = at), 
_ yi (x = al). 
i 4 
M = a (ht — - a pd fob - a') x fh (h! = a!) 
x : 
“= pas | n ff (x= a!) (al — ay) 


Note Lope2o7, If exceptionally the nesteert of the ‘swat rea- | 
uction of the compression sone of the concrete by the ste & 
sectian F323 Vs not permitted, on which the calculatton Vs here 
based, than wast the formulas 16 and: a7 do the “Prussvan ‘Regu 
artvans be. propery ‘BBPVOYOD. eet Hie . F 

The distance ef the resultant of Dy or r Be. from the BST Line is: 

Kus i 
£16) (alah) + OF ae (at - 3) ig 


riawee 


a a BOs WR SAR 


bp X 
1p ol to x —=— 


(important for the - Wc igame ness of the shear stresses), then is:-- ni : 


PLT ° ‘ ear eat spk i ake 
"ae pe ad fi sa ve 
in | b 
d, = (M in m kil, b in mw, h! in Ca. 
1000 kil/cm? G, = 35 Oy = 40 Op = 45 / ont 
0.0 v = 0.433 . v = 0.390. ¥ = 0,358 
0.2 10.418 i Opera ais, 0.341. 
064° Eo ee 0.402 0.868 0.324 
0.6 0.885 0.340 0.805 > 
0.8 . 0.387 “i iGua@iee 0.286 — 
1.0 0.349. 0.302 a 626G 
1.5 - 04299 0.247 0.204 
o, = x = 0.344 h']) x = 0.875 bh! | x = 0.402 ht 
1200 kil/cm? | 
0.0 0.457 0.4141 0.375 
0.2 0.444 0.897 0.360 
0.4 0.430 8-0, 388 0.845 
0.6 ogee te fey 0.367 0.330 


224 ra ; Bh, ek ae 
0.8 0.400 0.851 0813 , a 
8.0 0.385 0.335 10.208" | 
ss) Bs 0.343 0.290 | 0.248 
i x = 0.304 bt x = 0.888 b,x = 0.360 al, 
» & = oa eae, ° ie = wb hb! ° , ed 
Sc 
0, 5 bin a, (ah inven, 
1000 kil/ cm? Op = 35 Op, = 40 Op) = 45 
0.0 w= 0.602 w= 0.750 . ws 0.905 
Geet es) ne Rae 4 0.815.) 0.994 
0.4 “A? HOF00 RS OBS 0 Cie. en aL eae 
0.6 “i, gba meee Ms i il ems 
0.8 ese 4 | ib Petcare ti} 
1.0 PyGe926 (Un 46860. ed Gee 
16% CoD BIO I Ys i San) tee ie a 
ee x = 0,844 ht x = 0.875 bh? x « 0, 402 al ee 
1200 kil/om? I AN i lr ane SS Nd 
0.0 we 0.448 we 0.555 w= 0. es : 
0.2 | OATES BO aie ee 
0.4 fea 0 BO an OMAR Oa BO a ee 
0.6 0.b88 2. (0.604, yo Othe ae 
0.8 ES OBITS Eg OID iM OAR img 
1.0 et Ones ‘ON8a8 "4 y pee 
1.5 0.789 —@.110 0 1.48 


= 0.304 h! = 0.383 h' =—-x_ = 0.860 ah 

Determination ae stresses in ae steel reintorceuent. 

The mean tensile stress in the lower steel reinforcement it. 
is found py the aid of the formdla deduced on ue aoe 


hi + x 
o, =n Sp ¢ (1a). rae 
And the mean compressile stress in the upper: steel ween e 
went £2 py the aid of the formula:— ee ee ge | 
O6 2h Oh oe i | (19) . 


f ee what concerns the: design of a doubly reinforced conc- 
rete slap, the relations found for a simple reinforcement are 
also true here. On p. 258, 259 is given a Table for obtaining. 
tne Gross sections of doubly reinforced slaps and beans, made. 
by Geyer, Rawk Leipzig, which’ corresponds in form and arrange- 
uent to the Table on page 288 for single reinforcement. (See 
Aru. Be 1913. p. 81). Tne assumption is here made, that the 


iG 


225 
that the compression rods lie at the centre of gravity of the 
compression triangle, thus being at the distance + from the +. 
top of the slab. 4 : 

Kote. ws Ds 2~ Bo hot. doce MOT always Ocour. Ona wakes a? ag 
saal\s as possiore, about io Gepth of eeau, but never Vess than 
Le Po OWe 

But tae case usually pontine: I that the depth h is given, put 
single reinforcement no longer suffices, Since then 0, would | 
be too high. Then one sche hehe edi reinforcement and | nora 
brated moment isi-—— ae ao f 

Me pues es iy | | 

And this requires for the. given stresses @ special compression 
reinforcement Ee and at the same time an inorease of the tens= 
ion reinforcenent. Assumed is a Pah utilization of the 
wost distant stresses, given are h, b, a and a! (in nm), O»— and 
o»(in kiVom*), as well as i easionnanre concn wm nee aw): 
SG@ AvVWe Be. ABii. pe. 33. ie 

Toen according to formula (8):-- 


x=—— are hes ecordnig oo Lier | 


Partial lee Max 5 b x oy (ht + abANate Sore LIAL, |b ae (20). 


Ta qoep tae eet —- x). 
O(x - a')(h' - al 


e) 
ai 


Compression reinforcement:——j|f} = Me 


a 5000 » 
3 


Tension reinforcement:— fe 


For the special case that 0, = 1000 kil/cm? and 0, = 40 k/cm?, 


M ome ws 
£ 1 eM Dp emnenies i+: 75: Dd. h 5 F ‘ ae, 
ORAL a: 8(4 — nm) 
pit RO ee Gene iit nee Bi 
EO ee 


Another method for designing doubly reinforced slabs is the 
following: 2 if the ‘bending moment M and the cross section of. 
tae Concrete are given, then the permissiple pending noment M°- 
18 computed by the Table for slaps (p. 238). for-the fixed max 
luum stresses, and also the corresponding cross section £2 of 
‘ne steel. (Thus without reference to a compression reinforce= 
weat). Then ‘isi—— 


Rol 
es (28). 


= 3(c,.- 1) fet. | (24). 


further references are made to the papers published in the 
technical journals: for example, .B and #. 1909. p.177, 225: 1. 
1210. p. 114, 168; 1912. p,72, 167 (Suenson), 201 (Landmann). 
Arm. B. 1911. p.i0 (graphical solution). —- Zeits. d. Aust. 
ing and Arch Union. 1911. No. 18 (Lichtenstein's pucramgle: also 

ee Arm. B. 1911. p.302. 

ixample &. Fig. i143. 

for a mowent M = 1600 m kil the maximum stresses in a simply 

reinforced slab are obtained as:— 
= 50 kil/om? and og = 911 kil/cn*. 
Given: h = 15 cm, a = a! = 3 cw, fT, = 16 cme. 
1. It will.now be investigated, whether by the addition 

of a conmpressile reinforcement toe stress dp may be reduced 
to the allowable. Baxsnun value of 40 kil/cm%. The taickness of 
tae slab must not oe greater than i5 om: further if ‘tne. compr- 


essile reinforcement £4 =f = 16 cw?, then :-- 3 ye | 
15 x 82 ff (ib * 52)? 30 | a 
X =< + a joo” * 400 (16 x 2 . i6 x 43) — * et Scum. 


36 x 15(13 - 5) 


Og sone ere = 864 eilheet oe 
36 x 15 (6 = 2 


- 160 9000 

ss “/335(16 - 1.68) + 18» 16 x 0. Gem dy 

Z2eNbat steel cross sections are to de. chosen, if for tpe = 

same thickness of tae slab (45 cm) and tne same. moment (1600 
u kil), the two structural waterials are to be stressed to the 
ire limits, 6, = 40 kil/om% and o, = 4000 kil/om?? 
According to Table of slabs, p. 268, x = 0.376 x 13 = 4.88 om. 
Compressile stress in concrete. (according to p. 256), De = 


49 4 hs 
ve ex 100 = emma 9760 kil, 
iquation of moments (according $0 formula 16) :-—- 


= 36 kil/cm?. 


4, | 
160 000 = 9760 (13 - a Jt Dy * doy thus *Dyy's ASB TAKA. 


condition of equilibrium: Z2 = 9760 + 4457 sausten kil. 


Tensile force in steel : Z = o,f.- e a =. 14.22 cm*. 


Za7 


| 2.88 
According to formula (19) of = 600 case 364 kil/cm?. - 
Compression in steel: = ff ol tous £3 = —- = 12.59 cm?. 


The | preceding calculAtion may be simplified, if one makes % 
bhe assumption (Like Geyer, p. 259), tnat the gravity axis of 
bhe compression. steel coincides With toe gravity akis of tne 
compression triaggle in the conorete. Then again. x = 4.88 cm. 


fe f Panis arpa eh ee 
=D = 2, 6, = 14.40.x 1000 = 14100 kil. =) 14100 ke 
. On the compression are of .tne concrete comes ae x Db = 9760 me 
Tnere remains for compression steel 4340 ke 
iy Bias shal bitch about 11 cw&. 


ay x ay x x o/3 * 400 
3. By tae aia of the formulas given on p. 260 for tae 3 oath 
ecial case of o, = 1000 and a) = 40 kii/cw2, one coues wore 


quickly to the same result. (uM = 1. 5 uw tonnes, m =O ib4. aay 

= 1.6 # - 1.282 PS ee 

ne en eatenaras te OR a Raise cbr Ot EER a weocgmre. 6 oo) a. 

te * Oa te bk) 2-1 Ba = 0-464) = 14.2 on 
fi = Bact ie aaa ot iY SLi TOK O x 0. 43) = 12.6 on®, 


si 348 x §.154 
4. Asimilar result is given by eaokpiga! (28). and (24). 
age - bres = 0.300 # WM, tous M° = 1110 mw kil. 
= 0.390 YW° = 9.77 cm? ae 


P63 : 1600 ae 
' "be = ———— = « . a : 
Then. by Sra fe eet 14.0 cine» 


And vy formula (24), #4 = 3 ar Th ~ i) aes iahe.t : 
Example. 9, (Pig. 144). ee aie 
Toe beam treated in Example 3 wight have a Kept of only 60 
cu. Toe use of the Table of slabs (p.2 38) very soon shows, toatl. 


a2 simple tensile reinforcement is not sufficient: for already 
for a ratio of stresses, 0, = 750 and Op = 45 kil/ow?: — 


(a = a) = Q, 334 fw = ¢¥%4x 47.4 cu, thus-h = abt. 53 one, 


Let M = 7500 m kil = 1,2 m tonnes, hb! = 0.9 x 0.50 = 45 m. 
According to formulas (20) to (22), for a, = 1200, dG, = 40 k/om?. 
= 0.383 x 0.45 = 0.15 u (p.258).. 
Me = Tab 298 * 0.88% 0-db ¥ 401= 0510 “294m aenee- 


228 
PL = 2.94 meena = 18, 2. i 
° 1200 SOL NO fee ¢ 
5000 x 0588 x 0.15 « 40 , 2000 2.94 . 
DS nnn nae Ft Be Tom? . 
: 1200 ‘@agOOe 0.40 fc Lee 
The compression reinforcewent is thus greater than the tens~ _ 
10n Ryrppe cari: If one desires to make poth. reinforcements 
equal (ff e )» then use Table on p. 233:—- Ki 


; | oF ad 
Por o, = 1200, on = 40 kil/cm? ana 4 7 140, 
at = 0.353 * 140 = anout 47 cm, ay 
f, =f, = 0.8383 * 0.38 x 47 = 14.9 cm2 = 5 rods of 20 mm. 
Since the covering layer is 2 cw, thus the depth of the beam 
way remain = 50 cm. The compression rods, that tareaten bo : buc= 


kle under a neavy hive. loaa, are to be connected - With tas. ten | 
sion rods by strong stirrups, as in Pig. 240. 


+ RPG malay ee 


fixamphe 8. | 2 | | 
Given a moment M = 12 000 w kil and widtn.of beam = 0.30 u. 
Tne Limiting values o, = 1000, and o) = 40 kil/cm? must not be 


sxceede ed. ws soogrdin to the Taple on p. 288:— 


Ri © #e Ke qui ved 
/B ie Je wn ane ma Cm pees of bean. 

/ | | Concrele, ‘S) 
| : We kd 


BA f20 039x200= Pyeu Ope XENEXO.30 = Te 40.252 0 
Z Baobh 034K R00 = 66» 0950 KBOEKOZ0= Z0-/ [06 ORRR RR 
ERA: O30RKL00 = 69:4» RFX 604X080 = Ra) aay 0198 BE 


4. fbb fe, WAY 7AROO = PRM TEPER BPR RO" BERET OPTED 


Note f.).p. 264. Hore without adarvrtrions for. (‘Stirrups | ond bends, 
Por example, #3 = O. 8 Fes. concrete abe. 12. * 0404) *% 0.30 =o 
rei to 4 Re 


1.0 2 06028 me, ae i a4, Mh Ak: Be . a 
Stee, f, = 7 rods of 20 uaa =. 1 a WU per a ae Yeon, 
Fo. 4 rods of 20 ww dtancter = ry q" WAL, per as of beams 

Rota\ = 2162 AAV, per a of wean. | 


A 


ah eS 


If the completely tamped concrete (including wages, materials, ¥. we 


aking and ‘removing forms) be averaged at 40 marks/m?, and the 
steel ‘(including material, cutting, bending and placing) at & 
U.25 mark/kil, then the cost ber m lineal of beam would be ab- 
out as follows:-—- : 

l.f'g O. Concrete = 10 mks. Steel = 4 mks. Total = 14 uks. 

eEg= 0.6 fe .Goncrete = 9 wks. Steel = 7 mks. Total=16 mks. 


= i .,.Concrete = 8 mks. Steel = 9 wks. Total = 17 nks - 


ie a 


hat. 


: 1.5 f4-Concrete <9 mkKS. ‘steel . he nia. Total = 21 mks. 
It is tnen already recognized by this approximate calculati- 


eer. 


Bia di 600 ect a ire tear did ‘Telnforoenent taba in ec- 


Neate rh 


tin 


4 W 

Rae aie a 
Pye tate 
ea fa ate 
Leb nah 


230 : 
Section -X. Calchlation of singly reinforced T-Beams. 
A general description of T-peams bas already peen given on 
p. 189. 1. Tn the calculation of [-beams are to be distinguis- 
ned taree Cases, according to the actual position of the gero 
iine in tne cross section (Pig. 145). 

Note Le Oe 264- welan’s experiments on T-beads (contrive. etc., 
Lust. Bug. Ona Arch. Union, Heft 2) showed that the slab coop- 
ovakiee tia SUPportvag. the Load up to breaking, and that a sep- 
yb te of the slab and sean Ve not to be feared, 

Pe of Gero line lies in the cross section. of tae slap. 

2. Zero line coincides with bottom of the slab, 

S. Zero Line intersects the rip. 

Attention should be called to the fact, that also for T-beans 
tne Calculation of the shearing stresses is of great ‘importance, 
not only for determining the width of the rip, put also for tne 
final arrangement of the reinforcement: on this see Section XII. 

1. Zero line lies witain the cross section of the slab. 

Tac adjacent diagram in Fig. 147 snows that for such.a posi— 
tion of tne zero line, tae same relations in the distrioution 
of tne stresses wast prevail as in a singly reinforced slab, see 
Fig. 129), that also formulas (5), (6) aad (7) on p. 232 also _ 
apply nere. Now for pb is not to be. inserted i00 Ch, Duta val> 
ue corresponding to tae distance between centres of ‘the ribs. 
(Sec Fig. 155 on.p. 274). Por the calculation. of. the shearing 
stresses the width b, of the ‘rib is important. The thickness 
of tne slap is d. 

2. Zero line coincides with bottom of slab. | 4 

Tne distance x to the gero line in this case equals tne depta 
d of tne slab: thus the entire depthiof tac slab is statically 
effective. The formulas remain tae Saue as for case. 1, except 
that x is to be-replaced by a. 

8. Zero line intersects tae rin. 

If tae gero line passes througa the rid, taen according to 
taé Prussian Regulations, -the small compressile. stress occur— 
pe +8 tne rib may be neglected. 

the stress diagram corresponding to this rule is shown in 
Hig. 149, Let the extreme stress in the top of the slab be o° 
(= maximum stress Op)» and that at the bottom of slab = 0,. 
ine effective depta is again a'(= h — a). From the known 


| x 0 Hy. 
oressure triangle -=2 , the lower part (x — a) is omitted. 


231 
Then prevail the following relations. 


: Piet eine d 
Compression D = Be See dp: tension Z = f, og. 


From this results D = 2: wien db = {, Joe 
3) x x- da 
Now —2 = a) hen. Gs ne 
mays ¥ ee he u Be og <—4 


apy, (257%. 


| 


The furtner development is tne following:—- — Zhan ; 


a} o . 
=2 = = » thus oil >x=—S 3 (h-a- x). 
E fe) fe} 
And since +“ =n, -—2 = ---—-&-.- ; 
iy hn} x x n(a! Pat x) 
6, = 0, © * » Like formula (18). (26), 


P.£6Y 


If taen in equation (25) ere supstituted the values just fo- 
und for o, and 5,, thea resulis:-~ ee 


ni, eee x-~a@ 
b 8) 4 nlm x 


Prom this equation is found by transformation a definite. vale 
ue for the distance :x to the zero line. Hee 


a bax ries a? 3 ms 
2 ee 2 2 e 4 a 


a 
d bp.x tif. nx =f, in (bp!) .+\—<<< 9 
—4 


BR CIEN Gower os a Ste 4p | 

Toe distance of the centre of gravity of the trapezoid, thus 
tne distance of the resultant D from the zero Line = y: it is ~ 
calculated as follows:-- i 


yim ea ee ae a8 


ie cd 
a Oy + Oy 

If we now substitute for o, the es found by formula (25), 
then results ‘(see Fig. 150):-- 


Ra 


wlio 
t 
j 
. io. 
j 
wile 
+ 
i 
| 


i) 
nl ee 
i 


; + (28). 


2 c a a)? 3 
Note Le Pe267. Or also y = - xs “<<< se ES Lx |= 
2 
a, then wy = 2 Ge 


To obtain the maximum tensile stress 0, in tae steel, as for 
slabs, equate the pending moment. Muay to the moment of the in- 
vernal forces, thus:-—~ 


M = Z(h'o=— x + y) = Gata (nt ~ ye 


a (29). 


PLO 


Op» = We Aa | data ol | 
For tae stress in the concrete as waxinun. Op according to ‘E 
formula (26) is as above. | 
Formulas (27). to (80) thus apply to the case when the compr- 
essile stresses in the rid are. neglecte . For aeep and neavy — 
oeaus, for example as usual in ‘beam bri ges, ‘Lt-is recommended 
to take into account the compression stréss in the hb ae La 
fig. 151, since thersby is eT ee 
ated stress value 0). | | 

Note 1. See Kersten. Beam Bridges. 3 ra eaition. ‘cpm taped 
SXGWPLS VS BVSO CALOMAated there. . i ) . 

For T~ocaums should not pe assumed too High \vabues ‘for. tie a 
iluifing stress Op, in any case not over 30. to 35 kil/ou?: for 
according to Pig. 152, the fibres lying in bacvappege suuliace 7 
oi the slab are differently stressed., Fibre a above the rip is 
stresse@ in tension in the direction 1<- 1° (vending. of the slao), 
out in compression in tae direction 2- pe (bending ‘of the pean) . 
But for the ‘mumeg fibre b we have only compression in bota dir- 
cctions (particularly in the direction 1 - be De way thus be 
also stressed in compression to a greater degree, and-not be 
ee ae by tension, like fibre a. 
ne use of I-snapes, as evident from Pig. 153, makes stirrups 
and bending of rods unnecessary, woen the upper flange of the 
shape is in the compression gone of the Tebeam,. Any special t 
attention to shear and:bond stresses is tnen not needed. + 

Note 1.p.269. Yot svurvpf reinforcements are burt rarely ewol- 
Queda, Since Chey are not economical, porticularly when. they 
extend Vato. the conpression zone. ALSO for the use of such sha- 
023 Wa veinforced cancrete canstructian, soifar as ‘justifiabole 
SONS LAer atten exists, mn consequence of the aGIfferentd oehavior 


Pe . “ 
SS Serta a GPA OLS 


233 
of the structural materials in flexure, the formation of cracks, 
Vs almost certain. ; 

Por the Calculation of such T+beams suffices the following 
approximate calculation. Let the pending moment .M be given, as 
well as the static woment:of the entire section» adout beti axis 
n no (Pig. 153): 


wid Bie. 
S =pd (hk, ie eas SS ne a a Fk t. 2 igh ? 


NOVe Ze $o%69. For wn Vs best aserted. 145) ‘since one must, con-~ 
svaer. that. the. dated “replaces Qn” ‘Vaportant | port hadi whe | concrete, 
(Aveo see B & Be 1905. sp. 274). | | ne CWB he 

Ff = total area of concrete $n PF, Then the distance x to |the 
zero line is founa py the relation :--— (by. = ob! = 3). 


B! 2 oS Pe Ee 
x? + 2(- au oe bX Ba (FP bh ie ison 8) aad hy? e 
p. h70. cht Po: | Sa cre 
If I = woment of inertia referred to ies. ‘Kraxis, theni—— 
: RAE Tarn ae ane ee ica ane: 
Tne comupressile. stress in conerete = Oy = bri ek (84) o 
Coupressile stress in steel = of = a DR ghe, Oh (82). 
Mia x 
Tensile stress in steel = 6, = =a steal (38 ye 


(v = distance from compression top of steel to x-axis in. cm. 
(a, ~ x) = distance of tension. bottom of steel frow ‘k-axis in. Cm. ny 
ixample 9. (Fig. 164). 
M = 250 000 cm kil, tnen using an “Eeshape, Nogual! Profile Now 


ao (I, = 4139 cm*, F = 33.4 cm?) :— 


a x 12° 
5S = 50 x 10 = 17 ci 2 BSR, + 14x a x 10 = a 


RB! = 50 x 10 + 20 x 12 + 33.4 x 14 = 1210 cu? | 
1210 Bel hs i | he SR kane 
2 + ghz. 20)y oe LR hala aoe ata eee oe 
‘79726 PSII TE rain eas oda de mace ae Re 
caus X = about S ca. if a 
I = 14(2139 + 33.4 x 4%) + <-=---- = 45 981 ou* 
yap 250 000 x 8 
Compressiie stress in concrete 0) = ---=-=-- = 43.5 Saaven 
| “ iid 961 


Coupressile stress in steel of = 14 --— HO) 2). =457 kil/em?. 
| ‘ 250 008. 22-8 
'sasile stress in steelog = 14 —--- he ae 1064 Torta 


[tf tne gero line intersects the rid as in Fig. 154,(x>d), + 


vicn x 1s found by equation (27). If the bevel between rib and 
“Lad pe neglected, tnaen the ROROES of anereia. becomes:~— 


es decfeciaiai tee bis Melati cs gabe vege: 
to the data in Section VIII. Then follows the & 
the. Tebean oo the ere ig d of slab, and + 


a0 for the width 0, of the rib (about 3). ail 
co cm for the height of rip, + 


ial os she Dkr and the. ey: vdak big oe fe a 
> il wand 400 sexak de Veesnens 
“to the mutate pe it ‘see p. 165, Ia disap ce 


erable in 1 economical. respects to take . bhe hexane: 
eat as possible, since the greater dead amd weight 


of the rip Mertens ay" Rds. in: ‘COnparisen care te ghee 


of thes. 


supporting ‘capacity. But frequently a fixed 


essary the obtaining of the steel section. The 
s of the concrete may not pe fully utilized 
limit, since the beams become too low and re- 
rods, which place the economy of such beams 
stion. Only on thé underside tae supporting 

be greater coupressile stresses permitted,--- 
ng reduction of the stress in the steel. (See. 
ce to this). For Téoeams as a rule, one proc- 
ably, when with the uueese possiple b= 


RIA. Rourte retuforcenent | as +n Section XL Bry 


eel ‘section, | nites ‘gale height ‘of rib  eakieues a) 
sections or rods in great number. Tae oeams also 


for a, the structural acight at command, so that. 


a 
3 
ae | 
£ 
a 
i: 


1 £2 235 . 
ine Goncrete is not stressed higher than about 30 kil/cm?,put 
o, is then fully utilized. With less height of rib the section 
of the steel in tepsion must be inoreased, and if necessary a 
compression reinforcement must also be. provided. Such an iner- 
ease of f, (for constant M and constant dimensions of the :rib), 
only sonnet the stress. @, in steel eae but tae compr— 
essile stress 6, in concrete slightly. + : 
NOLS? Le Po®IBZ. 1% for the sane T-vean the. bending mowent » cand | 
accordingly: the steel sectian » Te ve aouvled, “whe sivess To sie 
the steele wot materially changed, our. the value By As Anor- 
cased WH. CONSLAerable Segree. For 1a: Bebeaw | ko = 250. ous he = 
60 ow, & = 10 en, by = 18 on) Worsen finds: -- 
Jor M = 4,430,000 om kiV and {, = 8048 en*, 0, = 878 pens 
Oy = ted wiv\en? oi! | Fe: 


por XM = 2,860, 900 cm kKLV and 2. tart e1. 6 ont i= 883 estleaty tie ie 


Sy = 20.4 om®. te ae | : 
for making a design it: ‘1s ‘et ‘importance, is. os § the | 
zero line falls within tae section. of tae or passes thro 
ugh the rib. If .it falls: within .s the slab. (also sec: formula belie 
then» oppie 1p 
then the Fable on: p. 233 is Zaxmex ‘py eee the 4 “zero 


tine falls but skighatly apove the pottom of the siap.!? seoor- 


iy 


ding to the Table ian ‘be. sufficiently accurate: phe A 
# Jv oe ea 
n! = 0,60 (to. 0.60). rote ‘for. Op = 30 ‘4% 23 kil/oa?. (eB) 
238 one 


NOC Be VeBIS,. Wt. table on.p. Mee SWx can. design with. eut- 
{ictent accuracy in a\\ cases. Take the waxtoun value. for Bigg, 


Dut enby .@ sualler value for. Sp - (Wuder- 35 Ken), . wth wen. 


< 


curate Checking, O, Tesults sonewhat | aualler, on. tne contrary 


0) is somewhat ‘greater. = ie hae: LG hee ay 


Por the same Tkbeam resulted:— ; phe | 
Por x = 4 = 12 cm: ° of = 19.7 cil/on?, ee = “1170. Kii/ea®. + 
For x = 11.9 em (x<d),o, = 19.8 kil/om?, %e = 1169, ‘kil/on?, on 
And with a different steel section:—— 
vor x = d = 12 .emj.o, = 19.7 kil/on?, Pas = 1084 aieatt: 
for x > a = 12.33 om: g, = 19.7 kil/em?®, Be = 1084 kil/eon?. 
if tne distance x to the zero line is tuarkedy greater than 
voce thickness dof tae slab (Fix. 148), then is made the. assum 
Obion in désigning, that: whe compression force in foc concrete 
acts at tae middle.of tne ska, so that (x — y) = on.’ 3 


Ress% tle. 
NOVS +3e Pe 212. ‘the Bah cet iid catia, 22 of. fice cits mua des deh stort’ 


4 a 
AB. eis ~ a By ty mt, Seetan As % ros the top of the 
suol ‘Shange - hares Un. the 1 chara of the centre. net 


seording to sbdeata (29), with a sufficiently. decd 
¢ beam onan ts (85). ne a a Bagi moment Min cm kil, 


pas ele gat onion qd Ne 36)... 
& 2 


the required steel section in cm®, Wor a more accurate 
a os bs the stress io iares a ponewhat rune eae 


most eK. aks Westosiiate to ee maximum ichua. In. 
the Bever arm‘of the internal couple (h' — 3 = about 
tnoen would (Min m kil):-~ 
@ = 1000 kil/em*: ff, = 0.a24 Ji. ie: 
» = 1200 kil/em?;  -£,.=8.204 fu, 4. “7 '?* 
assumes taat the sero line coincides with the pottom 
slab (nighest limiting valus for Gp, tacni-— 

vot, 2 Of 
> = ---* a SZ, (38). 
aba the vaduived’ Kaka: ‘a! and the: ‘necessary steel 
f, with fixed stresses: ‘O, and o,, the following formu/- 
ae Sena Xi 


‘Be B16, 
solapeantia Whether the gero line lies Within .or - below 
the formula serves:-- 


(89). 


ing to tae fapke, v = Os 15 foro, = 1000 kil/em?. 
v = 0.14 for o, = 1200 kil/cw?). 


(40). 


(41). 


</ 


2a7 
The values for v, m and w are to be obtained frow the follow 
ing Table ey @, = 1000.or 1200 kil/om?, and for a, = 25 to 40 
kil/om?. = 1000 kilfen®. #: | Oy = 1200 kil/ cu? 
%p tae | ; 7 og, ee Ne a a 3 ie 
. 257) Cash Aid E67. To Bebe. |e Oelee (eed BOO | acado. dc a 
30' | 04162 7" 2.6056' | 1.0744) 0.143 16367 F  1.eR2 Ae oe 
35° | 0.140 | 0.076 | 0.968} 0.189 | 4.0711 1.008 | 
40 10.146 | O,9997".\ C.899 | 05287) | ya.e00.| igueoe. |” \ 
On the. estaphish | ment of formulas for designing, + see fur- oa 
caer B and B, 1912, ps47, 121, 296, 431, 453; 1913, Pe 898: AS ase eae 
1914, pp i”. ** Contribs. 1910, p. 88: 1914, ‘pe Aixxae. 14, -_ CON ae AN aaa Ta 
Arm, (Be 1911, “ps 126, 250: 1912. p. 429; 1918, ‘De hag 339, igeacy' 
369: 1944, p. 60, 86. | ES as eae ee hy 
Note Le peBTdA. Much Vavor sand. time, can be lances’ ial she. Pe 
of -auitable vooks of ‘Bables,. that: An ‘Qreat.part are. also, to. ey . 
used WW Waking Gesrgns for svaqve. ‘and oupports. Gertainly these | 
Tabbes ane Wn part: wade. without regard. to shear | and spond | stress 
oy NeStetance, and thus. noy souetines: Veoa. ‘whe Vanorant to whe eens 
choice Of wnevitaobe and wneconomical sections. ee ey, oy ‘ | 
As for the-useful and statically. cooperating breadth of ‘the 
slab, the Prussian ‘Regulations require that for T-peams the 
oreadthof the slab‘ between the centres of the rips on each es 
side for more: than one-sixta of the Length ‘of the ‘pean ‘shall 
not ‘be taken*into account: ‘in the calculation. | ‘The compression _ 
creadth pb is then only made dependent upon the width supported Ay Ae ee 
Wd the -peam, but not on the distance \petween these. For Lagan PY ge ee 
if the span 1 = 6 mand the distance B- oetween centres of rips ae Canoe bia 
= 3.0 mw, then fe: the greatest compression. width. a ‘to. 1S used a coe. 
in calculations is to-be used not 3.0 a, bat. only 2% = = ‘Bae yee er 
1 a8 the maximum vahue. ror obtaining the bending uonent, nate PE at 
urally the distance B between centres of ribs = 3.0 m remaing — ite 
ieterminative. In all cases, where the half distance petween ae Sea ae ee 
centres of ribs is less than- 1/6 the » ‘span are, sks placed = Be veh ‘a a US 
Otherwise the compression ‘breadth .b exerts no great ‘ingiuéiee: : 
on the ammamsissead amount of tension steel, but indeed on the Ga ees 
uagnitude of the compressile stress” dae ‘the concrete and the. . | 
1eigat of the rio. Tae value b = = does. not always ‘give: the. 
2conomically best solution, particularly for too thin slabs... 
Jne properly makes 0 no greater than 20. a. + To be. distinguish— 
od are B = width sof loading, b = statical width, and b, = width 
ot the rib. . ; : Sat 


238 : : 
uany Calculate only with b = 2 hn, indeed with regard to the & 
twwotola stress in the: slab shown in Fig. 152. ‘Pne concrete. sec- 
tlon ‘1s indeed increased, but the steel section is. mecereethy 
reauced. | ib baa 
fhe limiting. value -of ’b = = is indeed. arbitrarily assuned; 
for it is also dependent | On the thickness of the slab. The de- 
flection of tnis:slab is’ a function of its. span B. It. would be 
an error to make the distance ‘on centres of ‘the ribs. in every 
case egual to tne: ‘compression breadta of the concrete, enbire- fs 
ly aside from the fact, that only in rare cases is. one free. he 
alistributing the Pibs. The slab is: already strongly stressed 
in flexure, and only a partial» Cooperation | with the ‘beam can 
be attributed: to ite (Fig. 152). K ecg , ; 
fne Swi S Regulations ‘for a. uniformly diaveibeteds loading & eh een , 
fix only - as the limit of tne breadta. 4, or at most : 20 tines es 
tne thicknessof the:skab. fe ee cee § meee i 
fae Austrian Regulations | require phe. following: -- For Tbeans 
not more than-4 times the’ breadtn of tne | rib: Day measured from ith, 
tae axis of tae rib, may be: ‘taken: ‘as’ ‘cooperating ., ‘a8. the ae 
adth of tae’ slab bo be taken into consideration, or. 8 eee, | 
the thickness of the slab: as ‘the ‘corresponding halt. distance | i oe 
on centres -of the ribs; : the: least jof ‘bhese- ‘dimensions. is. soube: re 
taken. Slabs:with/less than. 6\cm: ‘in least. thickness must not a 
og taken into account .as ‘cooperating. for T-beams. Woees Be at a 
Pe ein tie to the War temberg: Regulations. (1912), the: wie ; 
tae slab iportion on geet sideris. limited: to. i/o of the distance - 
cetween supports, bat at most to:10 times the ‘thickness .of aan yr Rp meena 
slab, is taken in the’ calculations. (tnigknsaa of slab at Tess) 3 
gt 6 om). : * Oe gy ae x: se Tae aes aN 
With. the existence: of a. ‘partition wall: as. in Fig. 156, the 
Load may be distribated on: 3 ribs ‘by a. corresponding strengins fe allah BA aay Ci 
ening of tne skabs. (Pig. 156. ma) fae slab. is stiffer as tne USER OR ga St 
\nickness @4 of the T-bdeams is greater. Otherwise ‘eross: beans 0S Er 
are necessary as ‘in Fig.+156:b. If no doorway | ‘openings exist, ar : 
then also ribs: arranged: above. may ‘be: employed ‘a8 in Fig. 156 °;" 
boen One ‘kas nothing to do witha: T-bean. According to ‘Fig. 
0a, one is satisfied with strengthening the slab. xt 
for T-beams with different thicknesses of slabs (Fig. }157), 
Sné€ may assume-d as the ‘mean ‘valué of that thickness. ‘Then as 
rule oO, will be somewhat higher, but on . tne contrary 0, will - | : 
2 somewhat hess-than»results:from an accurate: ereidabeakt an. haces ah wie 


Z 


} 
i 


239 | 
On a gallery structure ‘in the Gity Hall in Dresden (Arm. 8B. ae 
1910, pe 293) dead weight was to be saved. The breadth of the 
20 em reinforced floor slab was somewhat reduced. between the 
oeams toward the supports, as in Fig, 158. aie Sal. 
At the’fixed simple: ‘T-beams there continuous: ‘over the supp- 
_orts are ‘known to occur. negative-monments, 30 that ‘bhe tension 
“Jone with the required reinforcement taere lies in ‘the section : 
of the slab, but the: ‘compression zone only of the. widtn by” Eg ne 
es in the lower part of the rib. particularly. ‘appropriate. here — Cy ae 
are double Gcenteneanel ss, toa make. abe’ fe resin aaa 


allows: ‘eacbnt stresses in: sragsicrnnie rahe hast 
tinuous bridge girders: and other .heavy structures, if necessa- 


ry» one may vary beh wine et pee ees ae deat bed vhs 


HOMGA TS» The. same purpose. “is attained“lasély “by. special | ie 
ession slaps as in hoe me t, ce or frie a eae tt: widenin a 


aids, only’ in Cases: where deep. arenes sust be. eatatlesfot prec 
ctical reasons. ee ean ih es COG. ae , | 
Note Le He BIWe ‘ersten. pean Bridges. 3 ra eatttony 
"inenes at the: rtubtarsar & 4. pad in mae percents 


in ‘question. Widening. insects at the support. as Nie 
onty Rah AES: a greater. peta surface, The, Sakae 


of greater shears at the SUPPOrl. , Bs ee 
NOte Le Pe 2B. Rxper\ments. of Woyss. & Froytet Go. ane showy, A Me 
Vhat 0 Continuously tetnforced concrete veam also acts as. ae | Coe as ay 


CONTVAVOUS BeaR, Gnd that the arrangement . of stroughy | meade. 
ce arohes Vs 10% the dveatest use. Bhe economical advantages sh 
of the avahes ts ahown by the ToVbauing data, that afford con. 
clusters for the wate reinforaenent of the ‘vibs, alec fer the . 
cnount of steev employed. Without stirrups. - keée MBrsoh, -Reinf - 
orced Goncrete ‘Gonstruction). | 
Beow 1 \withavehes), oregking boad = ek “Sonnes, amount ot | | 
\ae\y = Foe KL . ue. Se a aN } ee %, ( re % aa 


’ ah ‘ ‘g ¥ - f .] fe 1) Pe 
1 a Tien | Hl D auth eas h D7, eae ee A oT ar 
ee +) Ta hs Ai ty ; 4 aa Vee a | 


ry Fa) bs) , nf a) ; * 
OF pies 
Ae 


249 2 

Beaw. ELI Ywrthour | arches); wekakine Youd = core Townes, ano- 
unv Of steev = 9440 kids 

fae transition from .bhe slab to the rib is ‘likewise arched» 
ag in Fig. 163. fhe arches are ‘not to be made too small nere,. » 
not being alene ‘intended for the negative ‘moments in the slab, | 
but at the same bine must. take account of the fact, that the ae 
naximam ‘value of the shearing. stresses in the beam almost’ elw~ 
ays occurs “in the. vicinity Ot the - transition from ‘slab to: rib. 
(in the zero: axis). Slope. of. arch about ‘3x1. (for example: 15: D. 5 : 
om); sbeep arenes are less: effective. “2 for oraanental ‘ceilings, aes 
if desired, ‘mouldings may ‘be employed asin Fig. 162. as Ale 

Note Ze Po 2TBs flor. {hoors of | ‘subordinate \aportance to save TH, 


cost of forns and for. MOTE. ‘TPs progress. of. the work, one: then 7 
QUSnTLY WSSS NO. arches burt ts satis{ted with Nevenee, he. page : 
voaras 4 ncn: thick Larch. 268 m* 26d on), per ‘ rene ad | 
eas negative moments an the slab b° may be auieled? aga wea eae 

‘of tae slab:as in Fig. 163; for the location of - -. me 2 a 
Wngy 2208/20: tne | axis: of the rib, bhas” where the heigat. ‘et ee 
ne slab: is rere IE Ree uae the ribs noth feel 


suns he 
Yt = > 


Such allewed methods nl 3 tion aaa have shana a 
tnat rib’ and slab-are: penta ‘successively without<interrup- 
blone If this be the case -- with the arrangement of arches ay ee iy 2 
and sufficient » reinforcing : rods be. beat upward, ‘one may ‘gener-— PR Ss. hue Bagot 
ally owit reinforcement for the stress-over the supports. ev on 
Tne Wartemberg Regulations » recommend, +e: provide tne. ‘trans~ ae Oe han 
tion with 4 roupding or beveling, which in general is to. be | Me a ks 
assumed at = to,~.” <€xA@ (length /6 to 10), | 5 eee 
Tne usual values for the widtn b, of the rib are 20 to me ad tee ae 
om (see pe. 271). Fhe breadth of the rib must render possible 
in every ‘case the proper bedding ‘of tne steel rods; it must . 
esist both the shears’ ‘(Section XII) as well as also the nega-— 
vive moments at the Supports. Experiments of tne German«Commi- 
‘lon (Heft 10) nave shown, that the allowable maximum loading 
inereases with tne width of the rib, equally whether stirrups. 
"e arranged or not. If m be the number of rods'in a row (num- 


241 
(number “in the greatest row if set as in Fig. 163-3), then must — 
be at least by =m 2.5 d. PO aan 
Concerning the arrangement of the rods, reference is made to 
mie 105. 1 the distance s is assumed = 2.5. diameter, the dust- ei 
ance t = 2 @iameter. If one ‘caleulates with a covering: layer 
of 2 cm on the-underside of the rih, then the least: distance 
from the gravity” axis: ef the steel to the bottomof the rib, 
will “bez -= | a, ag Se ra i a | 
Note Le Pe 279. ALSO see .B & Bo 1908, De BAB, 4086 Gea SLR Np I ECT ou ck 
i. a = 2 em.+ 0.5 diameter, af steel rods: are in one rom. wae Wien 
2. @ = 26m + 2095 diameter, if the steel reds, be in two 
rows over. each -otner. iy Fs ea ilies YG ee aoa le Sv et 
3c" a = 2-cm + 105): diameter, | at tne. steel rods be in two ae 


co Sopmae opee ut Dy Eesha a) er 
< t " {tga a va ie Rie a : re sth 


sered ‘LOWS. | BAS ene et 
Note Le Be HEO*” One. Can WETS | mganan’ SVAaNEy An ease: ee ‘etnce Le ae hee 
whe gravity -axts of the weinforcenent Vs ower a he en ee 
fhe vertical distance ‘between’ ‘bwo ‘Tows of rods can be proper- 
ly ensured by staggered rods of ‘a>: to 20 mn diameter. as. in: hiker 
137, pe 251. ‘In, 20 "Gase | ‘gnould the steel be displaced during 
Uae ‘CONCPETIRNGE : (see Fig. 65, Ap. 157). For the hooks, bends. and es a i 
stirrups, see ‘pe 190, 194, as: well as Section XII. Not. 400 ate : | 
all rods should be taken (best rods of 16 te 24 mm, for Wagwys 3) 
sirders rods of ‘26 and 30 mm), and ‘about | half. of the rods: Ha. 7 
the pib are bent upward at the supports. ‘The. number. of ‘the rods 
is arranged according - to. tae existing shear and \bond stresses, 
(Section XII). Tae steel rods are to. ‘be connected. wita- ‘the -com~ a 
oression gone by stirrups (rods of | +) to 8. am diameter). eo 
If the distances between tae main beams is too great, then = 
to avoid too. thick slabs. is advisable. the. arrangement of sepe- 
rate cross ribs as ‘in’ pigs 102, which are ‘then also. to. be. cal- 
culated as T-beams. Tae ‘junction of these ‘cross. ‘pibs: wit. the Ty 
vain beams are-Likewise wo be arched. The ehoice-of such an - 
arrangement of beams ‘affords the possibility of repeated use - sip 
of tae ‘centering, thus a saving 'in-cost. If one is not “depena- 
cat on the arrangement of the windows, then the. distances bet 
ween the ribs’ase taken ‘at-i/9 to 1/4 the span. | 
Tae main beams extend in the same direction as the floor slab; 
tae are properly. added the compressilke- stresses: ‘an. the slab 
uid those in tae scompression zone of the main beam (also see -. 
nidl 152). But still the main beam may also be calculated. as 
T~beam. ‘Yet: SR % way be taken at about 25. to he 2 kiM/en® 


i 
Ps 


ee 


‘iw Ne 

bs i \ hy i bard oe 
a hoe 
% Pe » ~ i 2 
f 7: i oe s 

a rks eee A ‘ 

i 4 ; ? / - t ; Ay 
Rest bs é b i 
4 4 7 


om the necessary ap- ee tgs 
dietaceh i a (avout are CSpot Ath 


x. 
3 
ae 


a 


ae A ay a onectin is 


ae 
ik i 
ae, t 
yi, oom 
x 
aa Lig 
3 te 
/ raf 
ah Nid ’ ; 
¥ ? ae 
awe ne 
‘ e 
+ * 7 
; ay 4. jt 
hy ae 7 
‘hes a y 
“Bs? ¥ 
sia ae 
Ros 
5 
2) ve 
or t 
£' (i 
4 
ee vit 
: A 
al 4 
? , "er 
ae tore) 
et ite 
: AY beac 
q Nc ire 
Ve ye 
i. Mt hy) 
) See 
y it ae 
ad 
ci 
ph rs 
% 


“to. ‘the location and. kind of : atnsotarey aad =) me Ue ae 


Hie 


= - 209 oA. phastened conning = > 82 kil ae is 
09  kil/ou*. | Bdhto’ 

on centres = 3.0 Me = 2620" me thus a ees | He 
Stylin of slap’ a=. 10 om (optained ee eke Tete Wena 


| 8 supports for’ ealoulation, 1 = 6. 60 + + 0.40 Taper anaes 2 Aas er 


0. 25. Bf 
ae ep a 3 = 23 iil on, 


1is° s: on, ia yn? = as 16a) iy 


POTS 


4 under : bo has: “meaake ved ina eas for my iy neae ae 
oe airing 30 kil/oa*: ORS habeas knows: that the baage | i Sees 


‘has: (38), to. (42). 

Rhe | ae | ‘Of the ‘Yowve : 0% Slave ON. Ye aee (see 
gross: Vile - weaulte, os under: Bag i 
= 10.6 me, - (@hus oes ae a 


"ae 5 rods of 24 mm. ae 22, Sion? 
at “ae Todas of 20 wm with te 


a Mes M Py 
Care ty of. tae reinforceuent ; is te 


“936 kil/ m jin. 
700 kil/m ‘Lin. 


Ht 


48d for arches 


1640 kil/m lin. 
= 4 awe = i 004 600 mri L gr 
18 * 95.2 ¥ 36 + 107 = 110 


i 1640 x shee. 100 


“TO = 200 tb * Go.2 F710 .69 ams 
ye 10. B= 5 + i a ue 24 Che 


-6(2 * 10.8 ~ 10). 


ee ee ee 
a oo rue ie TAY T7724) 908 kil/em s 


yo ae ste 

= 190@ or = 37 ‘ifest Sa 

ve 908 is(35 10, 3) cast : 

ete ‘he Re 234. .1f One| WAKES xs 4 249 CW, Snen ey formulas 
ay ate ‘1s ee 2B kon" and 9 ig 200 a i 


the permissible limit+ One way establish a new calcula 
; the ease, Bile according to. ee tes the. two er 
: adpaweubed haa vinuer one dosaawa: 4 m/20.. 4 cms yy = e 


meat on ve! a far. cope! effect than On Rost 


| beens 


e. to o ie oka for the Limiting atres- | 
ages gag? eg | 


ye aha bolddols beeoatat my rip the distance x to the: Bero. 


SF ds ileus! that lini bing oibesiee biubes than 
m2 produce » uneconomical sectionsa ost economical~ 
2 use in all cases %p =. 20. ‘to 26 kil/ow*®, properly 


ide iu wham biel de nas shown, hia the cules eae hy 


Og = 984 'kil/om? and a, = 28 kil/om?. The reduction. of 


a: 


Base De . ° Base 3. flee 
G, = 30 kil/om?, a, = 40 kil/cu?, 
‘= 69 | = 6 


= 0.49 x 69 = 33.3 |= 0. 89 = 63 = 26. 5CW « 
h nae om a ig 32 cu 


= 0 .465%83 .8*2. 2 he 0. 75x26.5%2, ie = 

= 34.6 cu®, |) p= 43.8 con® 

= 6 rods of 24 mm \= 10 rods of BAS, 
+ 4 rods of 20 mm | 3 


ion of a floor ith hain aay cross. ‘peans, wito the hae Ff 


nding oo taining of aan B98 sha. | of cost, as. well ae 


Ane 


i 
at 
Paes 


ee CY 
~ « “Ay yl 


246 : 
04%¢6 Section XI. Galculation of Douoly Reinforced T+Reaus. 
nere 1s true the same, that was previously steted in Section 
Ik, Pe B52:—— one indeed optains by double reinforcement of T= if 
ocaus a lesser neignt of oeam toan o: simple tension reinforce- j 
uent, Dut on the other hand must count upon quite a high weignt 
of steel. Yet if less regard is paia to saving money than to 
@ possibility of the least structural heignat, then way aoubdle 
reinforcement pe of advantage, especially also if ine stress 
in thé concrete exceeds the allowable limit, but the structural 
nelgnt cannot be greater. One places the coppression rods in 
bac Vicinity of the top of the beam, distant a! cm from this, 
taken Crow the gravity axis of tne steel, ana On account of = 
ine danger of buckiing (see Fig. 144 b), connected with the rib 
portion py stirrups. ffor very neavily loaded oeaus tne small 
structural nelgnt 1s recommended for the compression zone une. 
usé OF spiraiyy reinforced concrete. (See Section XVII). 
Tos Hamburg Reguiations of i913 prescripe:—— #Steel reinfor- 
cement for strengtnening tne coulpression Zone of Troeaus is to 


ci 
Ss 


oe avolaed." rah 
As for obtaining the stresses in douply reinforced T-beaus, 
nére as for tae calculation of singly réinforcea =peaus (p. 
260), are to be distinguisned two cases. : | hon 
a4. Tne zero line lies in the section or bottom of ‘ene slab. 
The same relations are valid as for aouoly reinforced slabs, — 
inus apply formulas (13) to (19), p. 257. Also for preparing oe 
designs are applicaple tne metnoas given on jp. 200, 261. he Ye 
° {87 pb, Tne zero line falls in the rib. Le Re OC ee eae 
Toen neglecting the compressile stresses in the rio:-—— i 
Note 1. Peo 257. For vrvage girders Vt Vs vest to nor Mca veek 
Ve COWPTSSBILS Stresses Occurring In the ribs. The formulas ~ 
when applicable are Siven in the Hankbook for Revngorceda Gon- 
crete Gonstructrion (BVsensetonodau). Vol. 1. 2 NO @dVtVON, D- 
O04. AVSO see PIS. ADL. 
bas rent ee (43). 
BEAN: a Pelee aces 
y oy formula (28) p. 267. 
MX 


0” Tan yea Perea 


Og by tormula (18) p. 258, of py formula (19). 
is Gross section can be odtainea in tne following manner:-—- 


F Romie 
as es eng 
pe ie aa 


247 
ae Accurate Method of Calculation. 

Given are O, and 6p. One odtains SultaplLe values for b, a, 
b, and a, determines tne dead load, and finds an accurately 
couputea value for M. Tnen are chosen corresponding values for 
4 and a'. Tne furtner procedure is the following:— 

x by formula (8) or more simply by Table on p. 238, 

y oy formula (28) on p. 2675 
compressile force D in concrete oy formula (25) p. 266. 
Compression D' from the equation of moments 
= Dp(n' - x + y) + Di (nh! = a!). 
Tension %Z = D+ D!', and steel section f, = ° 


Ofs 
@ 


Stress in compression reinforcement py formula (19),p.258. 


Margie { D! 
Reguirsa steel section in compression ge 


e 
d, Pe Pema! ees ve of 
*°* 5, Approximate Method of Calculation. e 
Distance x to zero line as before. 
a 2 
Bae 2 Th) eer tetera be (45). 
6(2 x - a) 
Find steel section in tension|f (46). 
Requirea s steel section in Com 
eae ys See ache Bon 
: 15 (o' = x) - ba (x = a/2) 
BY 1 = = rs ee es es es ee es ee ee ee es ee ee e ( 47) e 


4 aes ! 
So Gaia 2S Game ey pene 


LePe2SBe OH Gerivartian of the formulas, see B & Be 1907. Pedd- 

for fixed or continuous T-beamws negative woments occur over 
tne supports, tnat are wostly greater than tne positive panel 
noments. At tnese places of tne T-peams tne lower part of the 
rio wito the preadtn b, cm now receives the compressile stres— 
ses (Hig. 175). © at suen places a aouole reinforcement 1s in— 
aeed always to oe found: for narrow ribs by calculated consia- 
eration of tne compression rods, one can optain economical di- 
weasions. 7lso see Pig. 138, p. 2d2. 

Note 2. Pe 288. In Opposition to FS. 17h, Were D, V8 equiv- 
alent to D® and Dy %O De 

A Example 11. (figs. 176, 177). 

A T-peam of given dimensions has to resist a bending moment 
®w = 1.000 000 cm kil. The height of the rib wust not exceed 
54 om: d is made 10 cm. The cooperating width of silao will on- 
ly oe assumed at b = 100 cm (see p. 275). iaat steel sections 
are to be provided in the compression and tension zones, if 


wae aller Limiting values of 1000 ana 30 kil/cm® are to 
PY (UL ALHEL 


he 


sree 
a oo 
Ath. oie 


ee 


248 


a8 
f 8 Accurate Mode of Calculation. (Fig. 176) . 
Taere is assumea a = a!’ = 6 cue: tnen n! = 48 cm and 
16 
x = 0.51 * 48 = about 15 om: (= 48-----—--—-———) 
| S3ed +, LO 
(The gero Line tnus falls in tne rio). 
= 15 5 gis as = 10.8 cu 
" er yee 10) " ; 
15 = 10 
sO 0 ------ 
15 


D = STTr MER x 100 = 20 000 kil. 


hk ee 
140004060 = 20 000 (48 - 15 & 10.8) + D'(48 — 6), 0 D! = 2038 k. : 


= 20 000 $ 2958 = 22 986 Kil, thus f. = “a=e= = 2294 on2k: 
30 x 15(15 = 6) 2b 3g? 


OC) = maaan = O70. kil/cn*, thas.f) = == 4°10 .9 cu. 
& 15. ; Fi a OTe 
Le Pe®%BVe OY = G6 OW VS Taken very Varge.e. 3 to 4 CW WOuld atso 


surfioe, since one has tn the Cowpressrvon zone oO greater vrea- 
ath than 04. for placing the compression rods Wn One TOW. 
o. Approxinate Galculation. ($ee formulas (45). to (47) 
x = 0.31 x 48 = 15 ca. 


a = 48 D+ sas =. 43.58 ome” 
Seagate gis: tay ; : 
rte 00 


See esi “4000 ~ 
_ id X 22.8 ( 43 - 15) _ - 100 x 10(45 - 5) i 
pale scan See —~——-~---------- = 9.6 on*, 
© 15 (15 - 6). 
Checking. (Fig. 177). 
a= 2 + 1.7 x 2.0 = about 6 Cie 
0, = 4 # 2.5 x 6.0 20 Ci. 
On account of tne shearing stresses Db, 1s taken at 20 Cll. 


f, = 8 rods of 20 um = about 25.0 cm?. 
Eine Oo reds: Of 17 wm = about_ii.4 cm?. 
eG ee GE. oe = about 36.4 om?. 
160... 10 Se "3025 * x 46 + 11.4 x 6) _ 
X= <--> ------~ 15.64 com? 
2(15 x Mga 4 #1400" x40): 
290 fea 
St ca 11.33 cm 
= X = Dt sperm hy ; 
ee 6( 2x — 10)) 
5 = 2 ee i Q00_ 000 _* ofp Bh SS 29.3 k. 


oD” ( a8 5 noe eon V4 "is [26(48 — x)* + 11. re = 8)? 
Je “4 _* 15(48 = x). = 915 kil/cm?. 
x t 


i! 
a tet 
f 4) 


: 7 


: 
z 
‘ 

hs 


oe 


hae @ 


"ibe 2 coupression ‘and. ae sion 
ae A Ae 2 % Ae rae § 


ee ead kil/em®. 
sion oe Grdrsedent therefore causes 2 reduction 


‘i 1 NS 
e Ss ress. Op 
$ 
Prat 
ar ee me oe a rT 
t 
( 
We 
4 ! 
fr, 
{ vf 
+ inl 
; a : \ 
‘ . A : : 
E i 
a “ie 
% 
, 
i 
: . 
J 
“ 
i 
r 


(& 


Bey ye 
Pigh 


Nae 


Py 
ite 


249 
Section XII. Shearing and bona Stresses. 
A. snearing Stresses. (Also see p. 209). 

So far in case of structural memoders under flexure, tney have 
vcen treatea for the soecalled normal stresses, the internal 
rorces that act normal to the plane of cross section (compres— 
ile and tensile stresses, Pig. i, p.1). In the cross section 
plane ltself ana thus tangential to it now act tne snearing or 
tangential siress, and there belong here indeea:— a 

1. The vertical shears as in Fig. i173 b. 

3. Ine horizontal shears as in Fig. 176 a. 


out 


3. Added to these are also tne oblique waln shears as in Pig. 
178 c. (See p. 293). | 

To obtain the maximum shears in tne beam is employed Fig. i171, 
as well as the Table of shears for continuous deams xiven in | 
tne Appendix. | | 

i. The vertical shearing stresses. 

Tney tend to oppose a destriction of tne slap as in Pig. 178 Oo; 
bnaus preventing a sliding of tne cut-off risnt portion on the 
otner part. Tne snearing stress increases Trow tne middle or 
tne salp toward tne support, attaining its waxiwum va alue gust | 

eside that. Tnus care must be taken for a sufficient Cross @ ‘MG 
section there, otnerwise destruction of the slap hed occur oy 


direct shearing. 


D294. Ve“ Soni ke | ee, ag 


In general + = pe > leans am 9 

Ho in cm a 

Since the compound wember consists of two waterials with it 
erent moduluses of elasticity, anda because it is assumed, baat 

ine shearing stress is uniformly distributed over the concrete 
and steel sections, one finds tne shear in toe concrete and = 
ine steel per unit area to be:-- 3 | ae 3 


v AN, | bE Be ee 


t ! . 
Ey tp % Bp. t fe * Be fy tne te ee a es 
V; | a hs ce te ee. a 
BE ell gemnapt naps Pays CAG). Sr ae is ae 
SAE Sheet ie ee a 


A determination of the vertical shears (perpendicular ive) the 
longitudinal axis of the slap) is only necessary in the rarest 
34a3e8, Since these stresses indeed never attain in ine floors 
usual in simple puildings to the permissible maximum value of 
t) = 4.5 kii/com? or t. = 800 to 900 kil/om*. Thus a fracture 
of the slab by pure shearing is not to ve feared. 

2. Horizontal shearing’ stress. 


NS £7 Rage 


ah ia 
fol 4 
ni 


ye 


250 ; 

More aeterminative for slaods ana T-beams tinder flexure are 
pnose shearing forces directed parallel to the longitudinal a 
axils. Tney tend to produce destruction as in Fig. 178 a, tnaus 
causing a Longitudinal division of the slab into two entirely 
separate parts. The layers of fibres w a and m'paladjacent exh 
10it aifferent lengins after the destruction. One (m n) is now 
stressed in tension, the otner (m! n') in compression, waile de- 
fore the destruction both fibre layers were of equal lengin a 

eae were stressed in the same sense. 

‘The forw of the shear diagram is evident from Fig. 180 c, 4 
At tae top of tne slap the shear = 0, and the same below tne 
reinforcement, thus for a distance a. From the top the shears 

increase more and more, until they reach their maximum value 
<9 in toe gero layer. If equiliprium must exist in the norizon- 
tally acting snears, tnen if tne tensile stresses in the cone— 
reve are neglected, that maximum value t° must equal the bona 
resistance of the steel in the concrete. Naturally also tnese 
shearing forces parallel to tne longitudinal axis are greatest 
airectly at the supports, viz:-- Vo, = A- 6 

NOtS? Le De 293. FIG. 1380 a Shows the AVsirVoutrion Of the sh~- | 
gorine forces for a homogeneous beam, PS. 180 b, that when + 
the tensile resistance of the concrete Vs taken Vnto account. 
phe @vetrVourtvon in Fis. 180 © corresponds to Guse Il © for a 
ruptured tension zone of the concrete. (See PIG. 12%,9-2222). 

NOS? Jo Ve2%WSe A Poole in the Appendix affords the dota for. 
tne shearine forces in ao uniformly Loaded veam on 3 and 4 sup- 
ports, aso see PVE. LIB. 

Toe magnitude of the shearing stress is found — as follows ¢ 
fiw. 180). One cuts the slab vertically to the longitudinal « 
axis at tae Least distance s from tne support A. Taen the mom 
ent of tne gnternal forces equals tnat of the external, so that: 

m= dt D6 Ss Viays- | 2 


Ven 
Placing s = unit of lengtn 1.0, then D = Ek ‘ 


The maximum snearing stresses are found in the zero layer a 
and as a rule must equal tne Likewise horizontally airected 
ph grees ie Os Es 
“id b= LOD caus)? = —W2x (60) Sie 
bac i 
Here Vinax is in kil, op and © are expressed in kil: L the ~iiax- 
lnuu shear t° then results in kil/com?. The greatest snearing 
stress is thus equal to the maximum snearing force at the sup- 


ak 


of 


vagy 


support, divided oy the rectangle of tne breadto of tne cross { 
section into ine ever arm of the internal forces. As for tne - 
lever arm, for simply reinforcea slaps and T-+peaus with x = % 
Cs b= dn 'xX/ 82) (ese! Pigk 120, carr @.*.° 
KOtS Ze Po®Bhe Approximately for O, = 1000 and Gp = 4oO KAL\ 
om Cs YW SeR4. 
Hor doubly reinforced slabs ana T-pveams witn x $ a:-— 
f er ee 
= ££) of (ho = al) ot dp n= (Bh) = x3) ve 
Bi Say 2 (Gee p: 257) . 


| 
| 
| 
: 
| 
| 
| 


po 2B4 : s, 
Note Se, The Prussian Resutortr1ons 2voe anorther formula, our 


wavoh Leads to the some result: 


rea Tb ae a th 
Xx 


3 
Ls 0 e ‘ 
wee ohn sel Cx eae 
9), aioe it o ‘i 
ee HED Ae Chua) 
4, 


~ 
The shearriné& stress on the upper reinforcement Vor 8a swallery, 
see Bxauple A of the Peussian Regulations. 
for siuply reinforcsa slaps and T-peéams wltn x < G:_ 


C= hme x + y, (ses pe Zoo}. i 
(SES oe 
Kote be po2Bhe APProximately for x Ma: To =| —-—ses———— 


for douoly reinforcea T-beaus wiin x ® d: 
Ceca mk Eyl See Deo 1s) Lipendo Lys 

Toe wagniiuae of the shearing stress 15 taus not only aepend— 
i on the shearing force V, but also on tne preadtn by of the 
rib and on tae neignat n of the beam. T° becomes Larger, tne ~ 
sréeater is Vyas, » Out the smaller 0, and Oo are Ccalculatea. To — 
avola too gréat shearing stresses also appear advisable as or 
oaa ribs as possiole (with arched junction with slab), ana a : 
preferably great neignt of tne beam. Tne widatn of tne rip plays 
no part in tne calculation of tne shearing ana bond stresses. + 

WOts LepeAWe AccOTaAINa to experiments of the Gerwan Commi- 
sion (Heft 12), the maximum Load Ancreases with the wiatn of 
the PLO, just the Some with or without stvrrups. 

Too great width of the ribo naturally acreases the a2oa Load, 
ana also VWaoreases the cost of Constructron. . 

Bb. Bond Stresses. (See p. 211). 
ne snear Qlagram represented in Pig. isd co snows that tne 


Boe 
Spearing Stress Ty in the zero pkane must equal tne pond stress 
t, Of bne steel in tne concrete. g By bond stress 1s understooa 
soe Value relating to the pond resistance between Concrete and 
Qne thus aas here to ao witn forces, that certainly act 
on tae surfaces of tne roas. If s be again placed = 1.0 cm, ana 
ce perimeter of all rods found oelow and contained in bd ou Ww 


yiato of ‘bhe (elabs='Uxlin cm) then t44*)4 00 parte Xia: Ue 


hoes To? yay! (61). 


Mote JoHeeSD~. But tO juage From wore recent experiments, Vt 
VS VEMY probable, that the band resistance has no Cannectran 
Vth the shearing stresses, that the cooperation of cancrete 
ana steev VB to ve referred to a perfectly mechanical oasis. 
(See abs oa kinks 

cVertnrogedy (also Satiger) even hints, thar the vond stress 
in the first Vastance Va connected with the change of tensire 
stresses WM the sBeeb,vand that the band resistance is first 
Laken UALO AGGOURtT, where. the fFirsr S|ensvon cracks Occur WH 
che concrete, thus in the dowoln Of the Baximum bending wnone-— 
Avs, Where without this, Wost steel reinforcement already exi- 
sts for other reasons. For freely supported beams thus the bond 
Stre33 AVMVUALSKES Toward the supports, as already stated on P. 
2145 OS to be Gesianated |antirely negriectadbrle, indeed for avan- | 
ever a 25 WH, ANG wWLth Lhe arrangement of proper end NOOKs. 
(ayso see Avw. Be. 1941, p- 363). 


’ {© 


foe perimeter of tae roas aot dent up must then Dde:—— 
j = ——°=s -¥8S . (See Fig. 182). aN. 
= .0 V4 wy 
iaos and Tbe ans one places, 1 = 4.6 Ki 
= apout 0.9 al, | 


‘ 

Cc 

Lame 

a 
Alt 

} 

rip 

oO 

Lp 


(nen U = re (Also see ips 298). 
: Qi . ip) i=) : Y 
yorable effect of tue stittrup (p. 302) ana of the ena 


“at indeea always exist, 1s neglected in for/ 
uLa (Ou russian mesulatlons. : 
Ke Lededeo. EUGH QUTOVNED the resistance %O SYVPD WVtH BtVT- 
bOUr 22 PeCe eTeater Thon without thew, Por Varge roas 
see Leneral\y of Vess VWWeortance than for sual Ones. 
ln using formula (51), to deciae trom ixample 6 of tne Prus- 
ian KegulabBions, 1t 1s inaeea necessary to consider the pottom 


‘ous! boose pent upward should not be inciuded. 2 


203 
(wSrscho o45 deteruinea by a series of experiments, tnat slippA 
ing 18 only to be feared on the lower straight rods). But oy 
.aber experiments, Tor example oy Bach (ferman Commission, He 
.ts 1g, 20, and Contributions on Researen Work. 1907, Hefts 
45 to 47) it Was determined, that the rods pent up cooperatea 
in maintaining tas Connection petween steel and concrete in € 
Une sallé Wanner aS the stralgnt rods, thus toat in formula < 
(01). for U shoula oe inserted tne perimeter of all roas, inclu- 
Jing tne bent ones. sngesser also joins in tnis opinion. (Arm. 
B. AF1OE pee 74) ie ©“ In any case a beam with 50 p.c. of steel 
pent upward supports more buen one with only straignt rods. 
NOLS 2. Po 296. Short extra rods at. the supports are injuri-. 
us, Since They Avader Lowerngdg, never can ve placed with suffi- 
GCVENL BCCuracy, And only reduce the section of the concrete. 
NOt]? SeP-20d. ALSO See Research Work, 1906, p. 457 (Funke). 
jo oe OASis Of n1S experiments, MYrsch has estabdlisnea the 
If HULLS i= t= Se : 4 
jao6n Only the straigot rods (wita ena nooks) are considerea, 
na tne entire oblique tensile stress (see p. 300). is received 
oy tus vent rods. (Mérsca, keinforcea Concrete Gonstrucéion). 
Note Ae Oeeec. Thus the bond vresistanceFis obtained anly half 
as great as oy the Frussion Kesulations. (Formula (51). The W 


Kurtemoere Regulatrvans eivoe whe some formula and require that 


», YRS LONG StVESs be entirely received by the vottom rods. 
'e) 2 : oa . 
To 


Oo hign &@ Dona stress way pest de reauced oy arranging wore 

sualier rods with tne same total section fs» 1’ for then evidee 

utly tne total perimeter U is increased. Formula (51) also sa- 

Ows, that the Dond stress 18 dépendsnt on the eifective neivnt 

a' or tne Lever arm of tae internal forces, ¢ = (a! - x/3): tne 
greater tne lever arm, so muco smaller is tne bora stress. In~ 
creasing the thickness of tne slapd aiso results in a reduction 

of the pond stress. 

Note L.9.297. Yet the application of this weasure in practice 
very SOON Finds Vis Limit, since Vt will not do to collect too 
2veat a numoer of rods Ha Vimrted space -- for exanple in 8 
2VVAers.e 

In consequence of neglecting tne tensile resistance of the 
concrete (see Fig. 180 bd), as well as paying no attention to 
Oe Stirrups and tne anchoring of the roads, tae bond stresses ~ 


eS 
- 


254 
oftén resuit mucn smaller. Furtner, it nas been es@ablisnea . 
by-Wany experiments, that the bona resistance of steel in con- 
crete 18 greater than tae shear, for example, that a steel rod 
Tiruly set in good concrete, when pulled out, carries wito it 
tae Concrete directly adjoining it. (See p. 212). | 

Important 1n every case is an ancnoring of all rods by form- 
ing end nooks. (See p. 305). 

On tne use of special bars with aeformed outer surtaces, tnat 
make slipping impossible, see p. 55, 50. “ 

NOS 2. Pe2IT. For example, for Kahn bors, waony officials do 
Wot require proof of the bondcstresses, if one fourth of the 
reinforcement necessary for Buay ¥S Carried through to the sup- 
port. OR | 

Ror simpie siac forms of medium alstance between supports it 
1S unnecessary as a rule, to odtain calculated proofs for tne 
stresses @ To) and T,, that they do not exceed tne allowable 
liwit of 4.5 kil/cn?: for almost always tney attaln a sualier 
value. Thus the pending moment M there remains deterainative 
for deciding On tne sectional Giwensions. Tnerefore it is also 
innecessary tO arrange stirrups and cross connections for slaps, 
et alreaay for practical reasons (providing for hegative moa 
ents at tae supports), sowe roads are usually bent upwards, - 
iines T-peaus a calculation of tne snearing stress is indispen— 
saole; for 1n consequence of the snear and bond stresses, frac- 
ture ab the supports may bé possible sooner tnan at the middie 
of the beam by compressile or tensile stresses. Very easily » 
way occur a Slipping of tne slab above tne rid. Shear and bond 
stresses are calculatesa in the same manner as for simple slaps. 
bub instead of b 1s tO DE inserted the breadin b, of tae Pid. 

For simply reinforced T~peams are tnen first required stbrr- 
upS and penas, when tne width of tne rid amounts toi—= 

b, = Vex 
To S 
{If one again places t, = 4.5 kil/cm?, and f = adout 0.3 al, 


; 


=< 


x 


uhen b,. = Bat (nere compare formula on p. 296: J = ~tex je 


Tous 1f for T+oeams the allowable snear and bond stresses 
aré to pé fully utilizea, then according to the official reqgu- 
iremenis, tne total perimeter of tne reinforcement must pe ap- 
proximately egual to the preadin of the rid. 

Hor Continuous peams over several supports a calculation of 


205 
tne pond stresses is wostly sup#rfluous: tons lower reinforcen- 
ent nere lies in tne compression zone ana the upper one is an- 
cnored witn sufficient security. 
CG. Benas in Kods, Stirrups anda ina Hooks. 
a hye pene. in Rods. 

At tne support of a beam under flexure occurs neitner shear- 
lag in a vertical or a norizontal direction, but tne effect of 
bneé shears 1s expressea in oblique cracks in the vicinity of 
tne support. (Figs. 66 f, 173 c). At tnese cracks tne tensile 
resistance of tae concrete is overcome by tne obligue principal 
seresses. Une internal forces acting in the sense of tae stress 
curves increase wWltn the snears ana are greatest above tne sup- 
ports. Since at tae supports the moments elitner = O or are neg 
ative, ana conseguently no tension occurs in tne Lower zone, 

a oenading upward of tne reinforcement with regara to the bende) 
ine wougcnts 18 not only allowable but even necessary. Many eu 
perlwents aave snown, tnat tae effect of stirrups 18 1lnferior 
vO that of bends in the roas. Tne more dent rods are employea, 
sO muco the wore tae deam ends are ensured against oreakiny 
cracks. + Over the supports tne continuous beams as well as & 
for tne fixing stresses of Heams are bends requirea. : 

Note 169-209. Upward vends im rods Wncrease the resisting s 
capacity of the ceam, because they receive the principal ten- - 
sile stresses acting in therir airection. Bach’s experiments *. 
(Contrios. On Research Work. 1907. Hefts 45 to 47) showed, that 
1 ki of steeb, which was necessary in the arrangement of the 
VEWArGd Bands In vYOds, wos suLStantrvally wore effective than 1 
kV in strrrups. 

For a uniformly aistriduted loading, tne snear diagram accory 
ding to Fig. 183 1s 4 triangle t, * i/2. Tne natchea portion 
of this triangle corresponds to a neignt =(T, — 4.5) and a len- 
2ia c. One now assumes that tne concrete 1s siressea to tne al— 
lowaole limit of 4.5 kil/om?, ana tne excess of tae snear is 
recélved oy tne pent rods. Tne remaining snear 1s odtainea by. 
wultiplying this hatcnead area by toe oreaath db, of the rib:— 


i Re me Ge: 
C - | (to — 4.5) i LS 
(Tai a 2.5)" To ue Roe ss i) 
Atv tae point where the pend is to Gommence, the shear way be 
valy Vo = Vegeaons . A grapnical solution is given in Fig. lye. 
Vo 
uo-Skear-srrambetto- = 4.5}- 


Ny 


Me 
ae 


ue 


he 


3. Alt ind ible tiara 


ey 8 


a) 
Tne shear triangle (Tt). - 4 515 is resolved into parts with eg- 
ual areaS,ana verticals througa tocir centres of gravity are 
arawn to intersect the x-axis. Taese intersections tnen deter— 
wine the polnts for tne reguirea bends in tne rods. 4 

NOUS 2ope229. Lt VB sufficrient to take the third point in © 
the First area, Gnd approximately the widdle points in the otv- 
Aer avredase 

ps 19 ne concrete will tous be stressea to 4.5 kii/cm? in shear, 
ana tne excess snear Fase ~ i, ) is transformed into a tensile 
stress at 45°. Tae total oolique tensile force is:—-_ 


Pett 


c¥2 : ae 

Z= Vo cos. 45° = (TT - 4.5) Dy pee ee hte : ote 
Bie 

VA mas 0.508 G Dy Ge ni 445) ° | ; (ds). 


Q 


If 0, ana ¢ de inserted in w, then results tae required tot- 
ail Gross section of tne bends as 


a“ 


fs sche 5 SN eV: ye ae 
i oat 3.5 C Dy (TT) ~ 405) for o, = 1000 é Ge esyy 
“= 3.0 ¢ Dy (%). + 4.5) for ao, = 1200 ; | 
If i = numder of pent roas wWita f!om section eaca, tnen the 
3 ' & As 
tensile stress in the steel,o, = — . 
1 Cen see 


Tne compression D 1s received by tne conerste. 

At tne support tne denas are naturally most Mer ante ity tney 
ust pe Qistribubed over the entire distance c, anda pe closer 
toyetner toward the support. The formation of oblique cracks © 
43 in Fig. 67 e (p. 161) will pest be preveniea, bae more rods 
intersect tae line of tne crack. A construction as in Fig, 184 
1s entirely erroneous, even if tne calculation be wade sonnel 
lng to tne Prussian kegulations. “ 2 he : 

Note 1. pe 300. The Prussian RegubLatvons make no etatemant S 


CONGEYHIAE Lhe ALStrLoOUutrLon Of the bad de see B&B. ABA. De 


13 of Supplement. : AEE: 


for the same distance c, Lower beams as in Fig. 135 require 
a Sreater number of pends than higner peaws, indeed not for = 
reason of calculations, but on practical grounds. Ii one desi- 
es to save a graphical investigation as in Wig. i392, then may 
» pae Commence Witn toe first bend at c métres from tne support 
at wOSt, ana distribute tne succeeding dends properly as in 
(ig. 185. (Toe usual way). The aotted lines from the pends sa— 
OulLa pe inclined more than 45°, inaeea so much tne more, tne 
isarer tne pends are to the support: in the lmmediate vicinity 
uf tne support they way be vertical. Toward tne middie of tae 


Co 


257 
oeam toe roas may oe pent at a less angle. Naturally wito reg- 
aca tO tne dona stresses a sutficient numder of rods wusi ds 
extended peiow siraignt to the support. Then if iaere no Long 
sr rewain sufficient rods for oending, tois may ps aiaea py 

eclal shear rods a as in Fig. ids, ov larger becring roas 2 
way be employed, Oent packwara in the beau. 

For odeams Wltin concentrated loads tne shears proauceda by the 
live loads continue uniform for longer distances: tne penas in 
sucn cases ars to be uniformly distriouted over tnese portions. 
If necessary, wasn toe numoer of dearing rods does not suifice 
for tne pends, tney may oe aided py obliguely placea stirrups. 

fig. 187 shows 1n what manner tne dends may be made with air— 
erent arrangements of tne reinforcement in tas rid. Tac trans 
oe to tae slant must be gradual: abrupt bends are disaavan- 
cageous. (Pig. 191). | 

be DeLFru ps. . 

for all beams ana Teocams ils recommended tne use Of stirrups 
(diaweter 6 to 3 mu), that enclose the tension rods as a wnole 
(Pig. 183) or separately (Fig. 189), and ena in the compression 
zons of tne concrete member. Stirrups proauce a higner static- 
al erfect of potn structural materials, for tnsy represent an 


+ 


intluwate connection of tne compression and tenslon zones, and 
especliaily py their tensile resistance oppose aestruction (ex- 
perimembts of Mérsco). por large longitudinal roas tney are of 
sreater lmportance than for small rods. It has been sstablisn¢ 
ca, taat oy tae iatiwate connection of all parts of the beam, 
tne danger of formation of cracks and of a yielainy of tas son~ 
orete in tae compression zonés is Lessenea in an important aey— 
res. In ali cases in design for manufactories and bridges the 
rangement of stirrups is of particular advantage, since taere 
tne effect. of shocks is certain. The stirrups make possible » 
o0tn a careful and convenient placiny of tne steel reinforcen- 
cnt. Panally, tas stirrups are toere aiso of especial value, if 
bone nelgnat of tne peam requires two or wore tamped Layers: for 
alreaay brief interruptions of a nalf nour may reduce tne res- 
lstance of the concrete to snear to a taird of the usual value. 
A special calculation of tne stirrups will mostly be omittea. 
Toney are indeed regarded as a furtner valuable increase of the 
Pesisting capacity of the peam, and one is satisfied py a cal- 
culated estimate of tne pendings of the rods, as given on p. 
299. In all cases of the common use of bends and stirrups, it. 


203 | 

provides for a constant opposition to all oblique main stresses. 
but if insteaa of pends eme aesires to calculate the stirrups, 
ae Gan proceca as follows:— | 

By toe formula (52) the value c is found. Now assuming the 
allowable sneariny stress in the steel at 800 kil/cm?, tnen & 
wae requirea total cross section of all stirrups for one nalf 
ine beam will bpé:-—— 


foe eae. net 5 Gest tke 
oo 200 300 ; 
If c and bd, in metres are ee tnen 
fo = 6.3%e by (agi eb) - (55) . 


Note 1. pe303. By conparisan of the two formurias (54) ana 
(S55), one VeECORNLZes also the econowrcal advantages of vanding 
the roas. 

If tne total cross section of a group of stirrups =f (accor 
aging to Fig. 183 are 2, and Fig. 189 are 4 separate areas), % 
tnén results the required. numbder of stirrups for one naif tne 
pea ati-- , y. ea 3 | 

12 Bee es a ee eben 
Accorainy to the Wuptembery KeguLlations, the alstance detween 
stirrups is to pe computed by:-- ae rene | 
Bie be CET ue tite lag pe : (57). 
Ea Oa 
Here t = distance between stirrups, 


section of stirrups for lengtno t, 
allowable shear in the concrete = 3 or 4 kil/ ou . 
aiiowable tensile stress in tne steel. 
Hig. 192 snows a graphical astermination of tne different & 
Gistances petween stirrups. Tae basal iaea of tais solution is 
tne same aS in the treatment of the triangle of water pressure: 
¥o8 tne snear Alagram is Likewise a triangle, waich must be a 
agiviaead into a corresponding number of parts of equal area, to 
distribute equal stresses to the different stirrups. In praci— 
ice for practical reasons, one 1s not so exact in tne aistrio- 


e} 
° 
il 


ag 


i 


c 2) 


ution of the 3tbrrups, dut is satisfied with 2 or 3 spaces de~ 
tween stirrups, that are smallest ait the support (15 to 20 com). 
tnereby tne placing of the stirrups is made easier and wore 
convenient for the workmen. It is always advisable to extend 
tne stirrups up ‘into tae slao and to bena the ends as in Fig. 
i7i: for experineats have taugni, that the stirrups receive 

a part of the shears by the tensile effsct. Tne effect of tne 


2090 
stirrups wili oe still petter, if their ends extend around toe 
longituainal rods in tae compression zone. (See Fig. 137,p.251). 
It is also necessary to arrange stirrups at equal distances « 
along tne miaale of tne beam (30 to 40 cm), since tnere under 
of only one nalf the beam snaears may also occur, 

In practice ons aas to reckon Witn a common effect of stir#/- 
upS8 and pends or roas. If bdotm means are to de taken into acc- 
ount, ne can proceea as foliows:— yal Pea Ete ome 

By formulas (54) ana (55):- 

fh-= 3.5°¢ Di. (%5 - 74. 5), and £, = 6.3 6 by (ty = 4, 5). 

Tf tnen to tne stirrups be eo ye about 30 per cent and er 
tae bends =~ on account of thelr greater efficiency —= avout 
35 per cent of the snearing stress bo pe received, then for = | 
o0tn weans would result:— a ‘ : 

f, = £4 = about 3 ¢ by (t> — 4.5). Soe sys 

Bxeerlments of the German Commission (def t 10) give tne fol- 
lowing:-- stirrups nave a substantially lnacréasing influence , 


on the magnitude of the bona resistance and on that of tas br- 


saking Load. Stronger stirrups or cioser spacing prevent une 
siipping of the steel rods and nave a favorable effect on bne 
Load forming cracks. On the contrary for tae oreaking ioaa Sim 
ailer st@rrups saow themselves more efficient taan larger ones. 
of tons same total weignt. Toe makiwum loaa of tos beam wito 
nooks is found about 51 p.c. Algner than that of beams without 
aooks, and Witn the existence of stirrups at tne sane time, ev- 
ch gdout 64 p.c. , 


'% tae toe following Table for different values of To) dv are col- 
ected tne distances c (by formula (52)) and ine sections fo:— 
i se Ki ifew* eran ln, Tyee ch ie Cus. | 

4.9 3 G OF : 

5.0 OS ern Ost baal 

Bie Oise ae ae 

5.4 Uieena Wer aiy's 

5.6 O's tess Owe 45 

ras Oed eras O.44 ,, 

6.0 Ovi 2, Opel oty 

6.4 0.14 ,, Ue Ore 

6.4 O2t Ores 0.84 ,, 

6.50 On LOis At 59 

6.5 O Sans 1S he 55 

7.0 O eLons's 134.-5 5 


a5 


(eZ Os19 11 1525p 
jee eo Soy ae 
7.6 Oger ak: 1590.75 58 
Takk Ove: Pte ee 
80 One: PAB DUI 
3.2 OS ann PAR: HCO 
6.4 OP . 2gn08 PB ats 
8.6 Oa, BeOS wigs 
3.8 Oi aa Setorey 
9.0 Oy aor es 3.33) 3; 
9.2 O328-7), etry 
3.4 Oey eas Pah Gliahe. 
9.6 Sh meet ae BOT at 
9.8 Oasis ARO! | oy 
1000 O L288 Aiba Oy. 
10.5 Orog a ie tou ty, 
ate iS 0 6800) Sey dsp 


Here 0, and 1 are expressed in metres. 

NOVS ~-. Pe SOS. The maximum value of the shearind stress fe. shoust—=wsk 
Vo: SHOULG NOt exceed 10 to 12 kill\om*, Otherwise too wany vends 
would be NeGeVsary. One should rather change the ratio of W? 
+G)eNe . . 

3. na Hooks. 

As previously stated, the ends of the steel rods must pe fir— 
uly anchored @n tne Concrete oy nook=-snaped ends: taney suds tate 
tially increase tne bearing capacity ana prevent formation of 
cracks. Men are usually satisfied with snort pends or SO" > Bet- 
ser are bends in a sewicircle of about 5 diameters. (Considere! 

3 nOOkey 2 Wig. 190 e). It is sometines advisable to add sepa- 
Cave ancaorsbars around wnicn extend tae enas of the rods (Fig. 
isO a). Such ena nooks make it unnecessary to calculate the » 
oona stress. Purtaer, see B and i, 1903, p. 121: 1909, p.i32. 

NOVS 2ePe SOD. ACCOVAVAL to experiments of Each, sinply vent 
xOooks Only -have 2qual effect as tne sane odaVLVanal Length of 
straigart vod would wake. Rods with diameter & 2 A\200 of dist- 
WNGe Ketween Supports should always have round hooks. . 

"Experiments with reinforcea concrete beams for determining 
soe effect of tae forms of hooks of tne steel rods," Heft 9. 
‘né experiwents were made in Stuttyart,and showed that tne form 
of the nook on swoota steel, and that witn rollea surface, nad 


Oo influence atv toe peginning of movement in toe hook, but with 


rue ti 


YT EN 


261 
tas stesi Last mentioned the cracks opened wore slowly tnan » 
With swootn steel, While the smooth straignat steel rods witnoui 
end nooks haa fracture occurring with the first crack, wito the 
otner reinforcements and according to the form of the hooks, 
fracture only followed with a maxiaun loading 69 to 96 p.c. 
ereaver. WOSt advantageous proved to be the round nooks Wwita 
transverse rods (Fig. 70,p.166). for end nooks with transverse 
pars (Fig. 190 a), fracture aid not result from bursting toe | 
enas of the deams, put by exceeding the elastic limit of the. 
steel. ; | 
The experiwsats of tac German Commission affordaea for tne s 
same quantity of steel tne following comparative numpers, 
Staright rods witaout hooks, 1.0 times breaking load. 
Straignt rods with nooks 1.2 times Breaking load. 
Straignt rods wltn nooks and stirrs.1.7 times breaking load. 
Oolique rods, nooks and stirrups, 2-6 times breaking loaa. 
lixperiments of Rella ana Neffe Co (B and &. 1909,p.62), gave 
tne following values (the stresses under the maximum load on 
tne Osam being calculated py tne Prussian Regulations, includ- 
ing ali rodsi-- ae 
Seaus with sbraignt rods witnout nooks, To = 20 kil/cm?: t= 
13 kil/cm?. ae 
beams wito partly bent roas with nooks ana stirrups, ope 48 
kil/om®: ty, = Sl ikil/cm?. | 
Austrian Regulations. For tne effect of rigot or acute-anglea 
nooks 4—fold, for tnose witn semicircular nooks 12-fold, the | 
disensions of cross section falling in the pending plane (for 
roas the corresponding times the diameter), is to be aaaed to 
» 4a adjacent sbraigat piece under bond stress. | 
‘Swiss Regulations. The reinforcing roads wust not be bent at 
2 less radius tnan 3 a at the end nooks, nor at less than 5 d 
at the pends: thus r : Bde Es 19 be, 
Transverse and @ongitudinal sections: of a T-pean sufficiently 
relnforced against pending and shear are shown in Figs. 101,198. 
Hxample iz. (Addition to #xample I a, p. 246). 


P30 


i 


Maxi Vy. = s2—- = 684 ki 
Maximum shear Vio, 634 kil. 
604 


According to formula (48): t) REE TEER Ouy 


kil/ om? 
By formula (49): t, = 15 x 0.7 = 10.5 kil/cm? 


i; 


as 


202 — 

[t 1s evlaent, that for slabs the snears perpendicular to 
tae longituainal axis remain far under the allowable limit, so 
tnat proof py calculation is not necessary. 

reinforcement 10 rods of 3 mm, thus J = 10 <x 2.51 = 25.1 cn. 
(Taole of rods in Appendix). 

x = 2.71 cw, thus 2 =9- 1,4 = 0.9 = 6.7 cn. 


oe ae 634 Rigen 
Snear by formula (50): to = _~--- = 0.95 kil/cu? 


634 ‘ ae 
pond stress by formula (51): t, = ae ar er = 3.8 kil/cm? 
PARw aT ep Om, ep har, 
Toese values of Ty and 7, also remain —- as almost ayes 4 
for slabs —— within the perwissidle limits. 


Hxample 13. (Addition to dxample 5 a, p. 250). 


ene 


17360 
Maximum shear V.,, = =s---= 6930 kil. 
x = about 21.0 cm, thas z= CO — 4 r? = 49 Cate 
_ 8930 5 ele 
Snaearing Stress To: Pana = 4.8 kilo (tous , gel tat Oe: x/ ou? 
49 8 Toisd tak 33 
Bond stress py formula (54 requises U = TN = 
’ ow - 
49,5 CMe : % Ws ; 
D 40%. i 


Relnforcement, 5 rods 99k 20 ww. The number of the continuous - 
straigat rods mast pe a = 7 roash put there is a votal or | 
only 5 roas. ! | | | ie 
If one desires to save tons cost for separate shear eee 
went as in Fig. 1865, then insteaa of 5 rods of 20 mm may be u 
used Smaller rods witn tne sane f., for example S rods of 16 wm 
Then two rods are bent upward. paces: , 
s i 3930 
U = 6 x 5.02 = 50.18 cm, thus t, = Zea eo To 
013 x 49 
If the rods save end hooks, ana if further stirrups are arr 
anged as in Fig. 101, p. i190, tne value round for 7, is juayea 
allowable. If all rods, thus also tne bent rods are vaen into 
account, tnea:—— | es | 


8930 RS 
A ier, tocar deme YY Ee 4.5 kil/cw? 
8 x 5.03 x 49 
According to tne Wurtembery Rexgulations, neglecting tae pent 
roads (diameter of 16 mum), 


Ts Beak eins = 8 kil/cuw? 
x 50.1 


ixample 14. (Fig. 192). | 
For a T~oeam wito 1 = 7.0 m span and ob, = 0.350 m breadina of 
rib, tT) was found apout 38 kii/cm?. As reinforcement serve 6 
roas of 25 cm diameter. 


1. Tne necessary stirrups are to be calculated. For purely 


te Hy ; 
Pe? 
Saye he 
Bh ce ha 


263 
practical reasons —- without theoretical proof -- further to 
lacrease tae safety of sowe of tns rods are to ve dent upward 
at the support. - 
The mode of calculatian under 1 Vs Bess to be recommended. 


\0 SOR Ys: ion ce ers) 


7 hi zs. 
G = a a me on 1.53 m (according to Table on p. 


¢ 


305,50 evs Osee x7 Loss 
fo = 6.3 * 1.585x 0.50 (8.0 - 4.5) = 10.12 cm? 
If accoraing to Fig. 189, one places around the roas two do 
aouble stirrups of 3 mm diameter, then tf = 4 x 0.4 = 1.6 cu?. 
1 = ---—— = 7 Tage dade 
309 ! 26 
ztne necessary pends in tne roas are to be calculatea. for 
purely practical reasons some stirrups will then be pepe ieee. 
C= 1,53 Cit (as oefore). 
fi = 5.5 * 1.53 x 0.30 (8.0 — 4.5) = 5,62 cm*. 
Two rods are pent upward, tous:—- | sf 
hip seod x Soo 153 (a— 4) 


Chaat PP eae Gy 
Bond stress in toe Lower 6 rods is:-- 
8.0. x: 30 
UW, = seo = 5.1 kil/ cm? 
657 685 


Since stirrups and end hooks are providea, one may judge tne 
value t, = 5.1 kil/cme to be permissible. The bending occurs 
43 in Fig. 192. * 

Note 2.p2-308. Only hose stirrups are indicated, that are x 
required vy Calculation. Burt attention was already called on 
ve BOA, That stvrrups oe at areater ALVstances ny are also to 
oe arranged an the widdle portron of the veam., (part 1-22 6). 

3. Stirrups and end nooks should be ssparated in the calcul- 
ations, about .50 p.c. of: the existing snear péing assignea to 
tae stirrups and about 85 p.c. to the bends. 

“By Pable on p. 3805: © = 0.22.x 7 = 1.54 mw (as before). 
a = 2,00 * 0.00 x7 = 2.33 on* 

Tnaen i or = 6 stirrups of 8 mm diameter to be arranged. 
py calculation Saffices whe pending of but one roa. Yet two a 
snoula pe bent with regard to negative fixing momeats. The ar= 
rangement of tne stirrups and dent rods may be accoraing to 


Te ADS 
Pile LY. i 


eyo 
Needs 
pris 


yee 


26d 
Section XIII. Tensile Stresses in Concrete considered. 
Tae rules of the Prussian Regulations concerning this, accor- 
aing to which 28 of the tensile strenyin or (if proot of the 
tensile strengtn is lacking) 1/10 of tne crusning strength is 
i? be taken, were previously statea on p. 208. (Also see p. 30, 


'“460). There reference nas already been made to the fact, tnat 
the consiasration of tne tensile resistance of tae concrete a 
scarcely coweés in question in tne usual cases of puildinys. A 
wain purpose of the concrete is the reduction of deflection, 
wherefore it would pe inadvisable to replace the concrete in 
beasion py a less valuable material (cinder concrete, sic.). 

W6rsch established, tnat the Prussian Regulations really re- 
quirs about a threefold safety ayainst the occurrence of ine 
first tension crack, ana tnat neglecting tne tensile stress, 
iaere ig always.a 1.2 to 1.5 fola security. 1 To this is addea, 
that already with Lacking values of tensile stresses, the aci- 
oal stresses are smaller than those calculatea. In all cases 
Witn Gonslderation of the tensile resistance, compression in 
concrete and tension in steel, not more toan the usual limite 
ing values of 40 ana 1000 kil/cm? will be utilized. z 

Note 1.) per oils won the siress in the steel the appearance 
of cracks have sO for an portance, since then the stress in 
the steer, that Previously was substantrally Less than given 
vy cCalculatrlon, Finally reaches the calculated value. 

Note 2. PoSiie» PVVArim established, that in taking ato ace 
ount the tensile vesistance of the concrete, as Limiting values 
Wust be Anserted for compressive resistance 30 KV cn {or eve 
aos and 20 kiv\com for T-beams. ou 3 . My 

For T—peams the safety against cracks increases at the loca— _ 
vions of the positive panel moments witn reduction of the str- | 
esses O, and Op, Witn the least possinple reduction of the dis- — 
vance a, as well as with the increasing proportion of the rein— — 
forcement of the rib, since the amount ofr the steel pecomes x 
less in proportion to the concrete in tension. On the contrary 
for slaps the existing concrete cross section is substantially 
greater in proportion to the steel reinforcement. Tne danger 
of formation of cracks nere pecomes greater, the Aigner the 
percentage of reinforcement over 0.75 p.c., and indeea for tne 
uaxiwum stress O,. | | 

Toe fipst tension cracks are extremely fine, scarcely percep- 
tiole py the eye, and only to be found in the surface layer: 


oe is 
tn 
ant 


t 


920 


266 
» faey do not reaco the steel for a long time. The possibility 
of danger from rust by these cracks is practically excludea,. 
Ine best means against the formation of sucn cracks is a good 
and proper distribution of tae reinforcement. The formation of 
cracks 1s tnen divided among numerous very fine cracks, tnat 
only open slowly under neavy loads. Wita regara to tne shrink- 
age Of tne Concretein dry air, it appears to Mérsca not 1m pos= 
siple, tnat py the required consideration of tne tensile resis- 
tance perfect security against tension cracks can not be at all 
attainea, since already pefore tne loading of the supporting 
weuber shrinkage cracks may exist. “ In bridge construction a 
consiaeration of tne tensile resistance was earlier introduced, 
and yeu in many bridges, tnat have already served for traffic 
during years, and were designed witnout knowledge of the tens- 
ileé resistance of the concrete, nave snown no cracks. 

Note 1.69.312. Already WH Section IV (p.149, Note 2) the ren- 
ork was Wade, That Mair Cracks way occur just under test load- 
VHES, When BOTS Thon the full Live Load va applied. Then are 
formed fine Cracks, that may Vater open under the smallest ay= 
BAWVG Lafluence, especrally with previous abit is Vn. the TeVWn- 
forcement. 

On tae propriety of a consideration of the stensile stresses 
in tne concrete, men are divided in opinion. It is alreaay pei 
ter to not take into account the tensile strength of the conc= 
rete (cracks form in consequence of bad concreting, bad mixing, 
variations of temperature, inaccuracy in determining the modu- 
ius of elasticity for concrete in tension). finally, one can 
attain the same safety, if the steel section be increased and 
ine allowable o, be reduced. But in alt cases occurs the. calo- ! 
culation of the cost of the economy. S In buildings the consid= 
Mie of the tensile stress in concrete has no value: tae = 

ean of formation of cracks is based on no conclusive results 
of experience. 1 fae calculation is also disproportionately + 
iengtny-ana tedious. 

Note 2. Attempts hove been made to avoid great Vensire Stres- 
Ses Ly Pr*¥evrous stresses in the reinforcement, thus producing 
artificrval compressive siress in. the. tension zane of the conc- 
Vete. For exanple, Lund proposed to cut threads on the ends of 
whe rods,and then to. tura up o sufficrently strond nut with a 
wrench. Srvarilar sugsestlans were made by yoenen in Cent a. Bauv. 
207%. Po 520. Burt expertence has taugnt, that al\ these propo 


ie 
4 it t 
Ui cdhe alate 
6 AN coe 
ce es 
4 


fers (i 


Te RS Me 
arte 
Tigh Poors 


267 
prOoposars are unsuited to practical canditvons, Also see Arn. 
Be 1909. pe 231. 

Note LepeoSid. For example, the Wurtewberd Regulations of 1912 
\ntentronally wold ao calculated consideratian of the tensire 
stress AS NOT Tequired, and also the Rowmburg Regulations of + 
1913. The Latter StVV\\ require h* = 1\20 of clear span in con- 
crete and oO suffricrent oreadth of rib, so that the ahearing 3 
stress in the cancrete shald not exceed 12 killow?, withtout » 
regard to the rerinforcenent. . 

Purtner, 8@ B & B, 1910, p.ifs, 1919, p. 124, 170, 206, 433. 
sent. a. Baus. 19kS, Boe. 7, lv: 4944, No. 26. == Ave. Be keee 
pe 158, 202, B87, B42; 1948, p. 481; aleo Bett 24 of Sermon 
Sowmmissrvane ) aN 

Tne Prussian Regulations take tne wodulus of elasticity toe 
tension just as large as for compression. The Austrian Regula— 
tions on the contrary, prescribe i, = 0.4 ig: the stresses tik ys 

ereby ootained must more nearly conicide with the actual Sires 

ses, toan do those obtained by the Prussian Regulations. oO 
a. Simply Reinforcea Slaps and ‘i—peams witn << ae .. of 194). 

x by formula (27). on gy 2670 > 3 wr coe 

Ond: Semel aaa See A US as 0 Eat 3 : AES ae 


00 » x® : o(a - x)? 


a 
~ 


as a 


+. on f(a =e ma)? 
3 
NOtG Ze Peo 313. For practical purposes awa (38) Vs better: 
un the fovrLlowringd form: -- *s 


M Xx 

a) = A i Q Md a 

bap A [x (= - a) = = ( = - a)] 
Z ee gs Bi tikee 
A. 3/4, h- x id a 
os “iar hPbd Ee A 
Hi, a ox oe ane 
To =ia- aoa Oba ° Pig ; C6ORa 


sPs2Doubly Reinforced Sisus and iabeawanml one de (ig. 138 
eis + (a = ijt al + Be (h - a)] | 
& 


ST Fae, ba ae - 1)(2) $ + + oa Wee oe | (61). 


oq 2 ee (62) « 


od ip ps cemuntaes s 
bux b(h x) + (a A 1) {zh (x a a!')2 + f,(h-a~-x)* |. 


—— ——e 
ot 


3 
Opy oy forwula Wee 


o, and of py formulas (18) and (19). p. 258. 


if Ong attarns Yoo WVEH a value, then Bust iaxsen ven the -@ 


203 
348280 SSGCVON Nie be Increased. 
o. Doubly reinforced Slaps and T-beasm with x <d. 


2 
--- + (n - i){f) a' + f,(n - a)] 
a 


R: = meses Cae ss PRE Ye ° (61). 

TE Wee ek [Nee ON yj a a o 

a Le, re 2 Sm eh LL OK vee ean) Fe Boi ye) a= x) ?'. (62) 
Sp, oy formula (53)., 

Meee ana of by formulas (18) ana BS 9 Poel opal ts ct 


(If one inserts n instead of (n - 1), then tne values of oe 
and Op, Will de more favorable =*, indeed in a very smail 
degreep O, will also pecome sualler ak a relatively less de- 


Ce Syngly reinforged T-peams with x > da. 
ay A yh , : 
3 + (bo — d,) 3 tonvte (a ~a) 


XK 3 eee ret a ea ake Cr ace a > | 63). 
De ib + (b= Dy) at Se ee 


y by formula (28), p. 607. | | ; 
M x nes ) ! (oa): 


0 OAS AD ANN NS NY A SS NY RE A A A TS A AED NY 


ey P = ew te ee eae ents cere eet cag? See wee SER oe 


bnkS (2 x- a)y + Te é}* (0,4) x°)! +n f,(n-a-x)?- 


On, diy formula (59), 5, by formula (60). 
d. Doubly reinforced T-beams witn x > d, 
b5 he eae F m pal 
“i= + (9 - oy)5 + (n= i)ifg(a - a) + f£in - a)t+ fh at] 
& 
» Serra a ANY CEG NR HPN CNTY OT Oe LEON Ree eR TT Ail oo) ae 
pyc td Oat a tee it EE) ; 
y by formula (28) p. 667. | : 
. on Mx ie (66). 
D2 Ds 


(x/me /2)4 vy + SP (Card) 2 +( nex) 214+(n-1) [£,(n-a-x) 242! g(xra!)*] 
Oo, OY formula (09), Og and of by (18) ana (19). pp, £587 
BP. 315, ixample is. | 
Given n = 14.5 + 1.6 = 16 om, M = 1eg602 om kil. 
o = 100 cm, f, = 11 om?, Vyay = 1416 kil.) 
Then with tae Consiaeration of tins tensile stresses by foru- 
uias (68) to (60): 100 x 16° oe Oh eG 
x = ee Se amc at 
LOG Ske 16u 4 ova se 
ie tat xt tina ba I 


bd 4600 (3.61 = 6.5 - 8 * 3.83) 


Z 
16 eal 8. 61 
an MOL ee ei / outs 


8,01 
ee iz! a = 8.61 Jog pe lg 
etter io * nppcarbeee ri pss soem i: 27.6 = 282 kil/cm? 
8.61 
foe value odtained for Op, 18 then Qnly allowable, if the 
oi > o s) > r Cm 4 meg “3 A) 
tensile resistance of the concrete = ri 250% = 35.6. kids comes 
or tne crushing resistance of tne concrete amounts vo 40) xn23.7 
= 237 kiifien@c! (see pyrans) 
Neglecting the tensile resistance, there resulis a compressile 
resistance of only 6. * 37.5 = 225 kil/cm? 
Caleulation of Snearing and Bond Stresses. 


iiin consideration of tne tensile stress in the concrete, + 
>a Shearing stress at tne neight of ine steel reinforcement 

“iS sowewnat less than at the heignt of the zero line. Accord™ 
ing to Fig. 180 0 (also see Example 17), 1t amounts for simple 


relntorcement to:—< 


Ore 
D soe On ig 1 AO Cae mace 
Wis sgh 
v : ——— o ¥ e G7 e 
bee iis pte) Salis 5 od (c7) 


for compression ana tension reinforcement: 


Vie ie OF aS Cig! amt eR 
Ta: = —HSd = Ae ---<=---— caonsaniceateia One x a 63 i 
Oo age Z iD 1 ba : | see 


Hor ootaining tne snearing stress at tns neignt of tne rein- 
forcement, tnere is valid tne general relation, according — to 


xXitter:—— i y 
“i xX ; cS . ye ps 


Here 5 ig tne static moment of tae part of tne cross section 
above the layer examined, and I = tne moment of inertia of tne 
entire cross section:— ; | 


Png 
@xanple 17., addition to iixample 16, (Fig. 196) . 
1416 B61 


T) (at neignt of gero line) = aie EE, 27.6 = 1.3 


kil/ om? 
ak 2 ae Soe 
S = »(t_s_x) oe (hie 3-2), + 15 is (a -~a-— x) = 


Lise ame gs” bale i 


=> 700 | ot “ eae LAE LES 2 pelx Bi San O70). 
P3IT l= nase a2 = 40450 Clg 
t+ $580 


Uo Latpeign+—of Tilt orceent)—==——s<=s=ss=— 


nfs 


4; 
nee ‘! 
y 1 


210 


Be i Gee : 4416 x 1970 
s' (at height of reinforcement) = ---- ° 
ae b g nforcement) was x a00 = 0.7 kil/cw? 
th b Oe7.4% 100 
at ti = S— = --------= = 1.6 kil/om?. 


U 4s 


Section XIV. Calculation and Construction of reinfor- 
ced piopped and prick floors. 
a. Riboed Floors of reinforced Goncrete. 

On Nov. 22, 1913, the President of the Building Officials of 
sberlin issued special rules for tae calculation and construct- 
ion of ripped floors, tnat ars verpatin as follows:-—- 
aa Reinforcea ribbed floors, 1 are to be calculated with & 

i= 15, according to the ministerial requirements for construct- 
ion of: structures of reinforced concrete in buildings, of May 
24, 1907, where oricks are to be regarded as filling material 
only. Accordingly only tne pure concrete section 1s to.be con- 
sidered in tne calculation. 
for the aetermination of the weight are valia the minist- 
erial regulations of Jan. 31, 1¥10, on tne loads to be assumed 
for buildings. There both tae ribs and the layer of concrete 
are to be taken at 2400 kil/u® 
The determination of the weight of the pricks is given from 
time to time oy official weighings on large buildings, and is 
to be requested in writing before the beginning of the first 
work. ! 
3. Tne required minimum thickness of 3 cm of the floor slab 
required in Section 14, No. 8 of the regulations of May 24, f 
its refers only to the separate reinforced floor slap witnout 


b 3/6 
cavities, out also not to sucn slabs, that consisi of T-snaped 


nw 


and other sections placed side by sliae, wnere tnen the slab is 
oeroduced py the junction of tae flanges of such suall T-peaus. 

for tne supporting concrete slap of ripoed reinforced concr- 
ete floors therefore suffices a thickness of at least 5 cm, An 
increase of thé thickness of this slab by tne upper layer of 
oricks can only be taken into account, if the separate bricks 
are connected oy full joinis of pure cement mortar, so that in 
tne longitudinal airection of the rib exists a united compres- 
sion section. \ 

Tae construction of a floor of nollow pkocks without an up- 
cer concrete slab is not permitted. 


Sor 


a aa | 
flor riboded floors without nollow blocks, whose slabs may ser 
ve as tne compression slab of an adjacent beam, it is to be & . 
considerea, tnat tne upper concrete slab, so far as according 
to Section 14, No. 6 a, it 1s regarded as a slab—-snaped part . 
of this oéam, must nave a thickness of at least 8 om. 

4. The snearing stresses are to de computed for the weakest 
part of tne riods witnout regard to the prick layers, and for 
narrow rios in woichn the mortar can only be grouted, must not 
amount to more than 6.5 kil/cm?. Only for ribs of at least 6 
cu widta, in woich an ordinary tamping of the concrete is pos— — 
siole, way @ sasaring stress of 4.5 kil/cm? be allowed for the 
concrete. eae | . 

5. Tne separate riods in general must oe reinforced with but 
one rod: only when the rib at the neight of tne reinforcement 
nas &@ wiatn greater than 6 ch, may a corresponding greater “num 
oer of rods pe placed in the rips. ie 

In tne determination of the distance a of the reinforcement 
from tne oottom of the floor is to be considered the thickness: 
of tne existing oottom of the hollow block or of the plate set ee 
to make the underside without joints. f 

6. The pearing of the floor on masonry must oe at 1 ae 13 | 
CH, and 18 to b6é so constructed, that the Pleo at tne edge 
aoes not exceed the allowable Limit. : 3 * 

7. Tne ribs under no Cirmumstances are to oe employed ra 


Wiles, peams, Out for stiffening the pbuilding at determinate 
jlaces, for example at the axes of plers, are ratner to be arm 
anyed special stiffening girders. ;ikewise tne rops are to be’ 


ee ancnored into tne masonry at the usual distances. — 
For riobed floors witnout nollow olocks, if tne ribs are lon- 
yer tnan 5 m, for a safe distribution of tne concentrated loa-_ 
as on several adjacent ribs, is to be arrangea a transverse rip RY 
of sufficient stiffness, put not taken into account ‘statically. — 
3%. The distance on centres of the rins shall not exceea 60 Cll. 
If instead of nollow blocks several of Klein's plocks wita 
Srooved surfaces are employed, the distance on centres of ribs 
way oe increased to 75 cm. 
3. Floors wita visible rios in dwellings must receive a pla- 
Stered celliny beneatn. 
10. Floors extending oetween cles | hand On both sides must only 
0? calcuLatea with a moment of —— ; only in special cases if 


vae-neoessany—fixing—ts—snewiy—and—tne-Constp opi 


ve 
COE a 


4 


J 


o72 
if the necessary fixing is shown, and the construction of the 
floors mene a i with that of the walls, may they oe calculat- 
et with Fe 1 Th this case alternately one rod is to pe pent 
up, tne other extending straignat througn. 

Rive 1. pe31%. Bee p. 168. 

11. For continuous rioped floors extending over several pan- 
els, as for other floor slabs, is not opposed a reduction of 
tne moments at the middle of the panels in the sense of the & 
uinisterial requirements of May 24, 1907, Section 14, No. 3, 
if tne reinforcement is connected over tne supports ana carried 
tnrougn without reduction, and if tne homogeneity of tne slaps 
is not destroyed py steel girders in the entire thickness of 
tne slads. 

Accordingly slabs petween steel girders cannot be taken as 
continuous in tne rule, put on slabs between reinforced conc-— 
rete oeams. Taere will be no account taken of the deflection 
of the girders (sinking of tne supports) in tne rule. 

for the junction of the slab to tne reinforced concrete gir- 
cer an arcoed thicksaning of the slab will not invariably be 
requirea, in case this is not proved necessary to receive the 
negative moments at the supports and the shearing stresses in 
ine slao. | 

For floors taat are continuous over several panels, for live 
loads up to 1000 kil/m?,tne bending moments in the panels are 
to be taken as that this panel is fully loaded, wnile the adj- 
acent panels only support the aead loads. If the floor thus ~ 
extends Over more than 4 supports, tne end panels are to ve xs 
calculated as endR& panels, the intermediate panels as miaale ~— 
panel of a slab extending over 4 supports with freely support- 
ea ends. ' 

Floors for wore than 1000 kil/m? live load are to be invesi- 
igated for the most unfavorable arrangement of the loading, i.e. 
no longer suffices the assumption of loading on a single panel, 
out rataer for calculating the end panels, botn the panel exa- 
wined as well as tne third panel of the same taree-panel syst- 
em are to be regarded as loaded, while for the calculation of 
tne middle panels, the investigation is to be extenaed to a 
system of five panels. Then both the panel examined. as well 
as the third panels at right and left must be considered as 
loaded. 


in wre ‘ . 4 i $b , - ‘ 


aa 


TW 


273 

for obtaining tne negative woments over the supports is det- 
sriinative for continuous concrete peams and floors, not the 
joaaing of a single panel, but the full loadiny of both floors 
4djolning tne support. but tne finding of this maximum woment 
acting above tne support may be savea in most cases for live 
loads under 1000 kil/w?, if the junctions of the floor Witn & 
wné DeausS and of tne beaus with the girder, abe Constructed for 
bné same womént, that would occur at the middle of the support, 
With tne assumption of a live loading only in one panel. : 

Note 1. 02320. See vo. 172. 


12. A special exception occurs for vaulted floors. Tnese fl- 


oors, whether they extend between stsel girders or reinforcea ~ 
concrete beams (on the pearing on wasonry ree No. 6), must be 
calourgaee with a Constant mowent at tne middle of the panel, 
oF ean tOr panels fixed at pota sides (miadle panels), ana of 


Bi ae for panels fixed at one side (end panels), when the 
/ & 


Ocaus or giraers are strengthened by an arch at the fixing DO, | 
int, wnose neignt is twofola ana whose projection from the mid- 
ale of the girder or beam equals fourfold the thickness of the 


floor. (figs. 199, 200). | Tae eane Se 


is. In the area “of the negative moments in nollow block floe 


7 


ors, ootn for continuous as for floors calculated as separaic- — 


iy fixed, solia concrete is to pe employed between the separa- 
ve ribs. Tne widtn of this influence area is to pe snown for © 


con tiayeus floors in pil cases, Ue vee oper tee eee wir 
va tm is taken for pts and with —=> or --- for = of the span. 
S | | yi 


Lz 3S 
(see Figs. 199, 200). ¥ 


To ensure an underside without joints, it is Tae & a ‘ 


cover tne célling with stone slabs. Hor otner ripbed floors 
wae ribs at the support are to oe made wiaer for the pefore 


uentioned rare 3 area CATE CEpORGE to tne calculation. © i 


~ 


upward are to extend into tne adjoining panel for the same dic 


neta. | 

for beams Gomposed of I—peams, tne floor rods may also pe = 
nooked over tne upper flange of the beam: put then for the neg— 
ative moment, so far as tne solid concrete extends, must upper 
rods pe carried apove the beam, in number ana diameter like 
tne floor roas. + 


Note Leped2ie See PS. B7 co (pp. 187) ana Note 1 on Pp. 125. 


iis 
Pe 


Me CE: ok 

[t 18 permitted in the calculation of reinforced concrete 
oeams, between which such floors are fixed, to reckon as in 
tne compression zone of the peam, the concrete petween the se- 
parate ribs in tne area of tne negative woments, and further, 
so far as 1t concerns ribbed floors of nollow blocks, also the 
upper wall of toe inserted plocks. 

for ribbed floors of aollow plocks the average tnaickness of 
tné Compression zone will be obtained py the formula:—— 


dG = -+--+----=--=, See Fig. 201. 


0. Brick Floors. 3 ; ” 
for the proper construction and calculation of simply reinf- 
orced prick floors, ine following regulations of tae Prussian 
winister of Public Works (Jan. 21, 1909) are of importance. 
<[né regulations for the erection of siructures of reinforced 
concrete for oulldings of way 24, 1907, find proper applicati- 
on wo plane floors of brick with steel eeinforcement, so far 
as tne static conditions, particularly tne form and location 
of tne steel rods, corresponding to tne assumptions, on which 
are based the rules in Sections II and III. 

Toe wodulus o elasticity of orickwork may pe assumed at the 
twenty-fifth part of that of steel (n = 25). The maximum Ccomp= 
ressile stress occurring in tne slap of prickwork, assuming 
vac use of cement mortar, shall not exceed 15 p.c. of the cru- 
Ssoing resistance of tne pricks snown oy official proofs, and 
in no case way amouwt to more than 85 kil/cm?. 

A concrete Upper layer for increasing the bearing strength, 
rah less than 3 @m thick, shall not be tonsidered in the calcun 
lation of tne bearing capacity: for at least 30 cm but not ov— 
cr 5 cm taick, may tne strength be computed oy the preceding 
rules for prick floors with steel reinforcement, tnus wita na 
= 25. Yet if tne zero line falls within the concrete layer, or 
if the Latter has a thickness over 3 cm, then the floor is al- 
wayS to be calculated as a reinforced concrete floor, accoraig 
to tne regulations of way 24, 1907, thus wita n = 15, wnen the 
Orlicks are to oe regarded as only a filling in the tension zone. 
‘ae miking proportions of tne concrete layer must not be lean- 
cr than 1 volg@ cement to 3 vols. mixed gravel sand. 

Tne snearing stress of tne flooring pricks must not exceed 
200 kil/om?,. 


Pheer s~ot—stet—feritz—tret—res+ 


o75 
¢Loors of siap form, that rest at. both sides on the lower 2 
Flanges of the stesl beams, and closely adjoin tne webs of th- 
ctams, way be rgzardea as oalf fixed and be calculated py 
formula x = == - Yet if the floor be constructed as T-pe- 
us, 80 that he steel beams are only loaded by more or less 
alstinct oeams, then is it to oe regarded only as freely supp- 
ortea. The same is true of such floors, tnat dn not rest dir— 
ectly on tne lower flange of tne beam, but on a raised support. 
To plane floors witnout steel reinforcement the preceding 2 
rules are not applicable. If according to their detail forms 
‘ney are not to bé considered as vaulted construction, and be 
so calculated, tneir deariny capacity as a rule is to be obta— 
ined py test loadings, that are carried to breaking. As allow- 
aole live loading is to be considered one tenth of the test 
loaging employed, whico produced fracture. The permlt is only 
Siven for tne test floor with the Cnoosen span, tnickness and 
uoae Of support, even if the breaking load may amount to more 
tnan ten times the intended live ioad.". } 
On this regulation may be stated the following as still exi- 
ending 1t:-- | Bie: | | : 
As a rule, aefinite forms of bricks are given. Since also 2 
r tae concrete layer also aefinite thicknesses are specified, 
’ ne! aead weignt of the floor in its true wagnitude can at first 
saucea in the calculation. The thickness of the mortar 
steceh tae oricks 1s never taken tco small. For pract- 
ice a8 a4 cule occurs tne prodlem, for a given M and a definite 
o. stress in the reinforcement, to determine the required 


«*)' aS tne waximuw Ccompressile stress. In 
igveanecwent of a covering Layer of 
concrete, (instead oi & [iiillg aot SsOpporting anytoing): it re- 


coe compressile stress in the oricks, and thus makes pos= 


in regard ub baa ee Cab Cede plage fioor: of hollow oricks, 

reference is made wd ine feliowise decree (of. Jan. 14,1913): 

‘for the data concerniny tne welgnts, etc., of plane brick 
-Loors contalned in tne regulations of Jan.31, 1910, relating. 
lo pulldings i _. (Nos. 18 to 24 a of the regulations and Nos. 
iS to 19 of the bases of caloulation), it is to be understood, 
tnat tne floors composed of nollow pricks only have the given 
iclyntsa, only if tne entrance of jointing wortar into tne nol- 
Lows—ol the Dress . 

Ne) 


+ ig 


i 


276 

aollows of tne pricks is surely prevented. If tnis oe not tne 
casé, aS now most kinds of nollow pricks nave open ends, then 
uust correspondingly higher dead weignts be taken for tne flo- 
or slabs, for example 140 instead of i115 kil/m? in paragrapa 
ig of the regulations, thus being fixed at about 20 p.c.more." 

Of special importance is the fixing of tne wodulus of -elasi- 
iclty of tne prickwork wita n Qos the cov— 
ering layer can oe taken as cooperating in tne siaiic efreci 


an 
ee 


Tae bricks beneatn 
in calculating the compressile stress, which was not tne case 
formerly. That for n = 25 a greater amount of steel is necess— ‘ 
ary (in consequence of increasing x) in comparison witn the 
Hui of n = id, alreaay resul ts trom formula (11)5 see 
0. 235. But for this ~-wita the same allowable On w the eff. 
ective neight n!' is less and Likewise the mwowent M (in conse- 
quence of tne smaller weight of the pricks). Tais even nas as_ 
that —- for tac same moment —— reinforcea prick flo-, 
ors require less reinforcewent than reinforced concrete floors. 
Corresponding to the Table given on p. 203 for n = 15 is gi- 
ven toe following Table for n = 25, which is estaplisnea ins | 
tne same manner, and can be properly employea for the cele nay: 
tion of reinforced orick floors. + % 
Note 1. Ped2d~e 


a result, 


A\Vso see Heramann, "Reinforced Concrete FLOO- | 


v3, Reinforced Brick Floors, and Artificrol Stone Steps.” Also | 
Boerner, BStatrve Tabbes%, 5 th edietrvon. Appendark. Ber\vin 1944. — 
.c (formula 9) (formula iope ess (formula 3) 
affective depta steel section distance x to zero dine. 
his ig BPS eolgiige x and “niin Ca. 
Moment M in m kil,widto bo of slao in uw. 
5, For slaods, = Ji, = Je 
ae For beaus and t-beams, a A 6 = Ji bd. 
12 “Ba84!2%% .880°a | -Ber3st0°P> 4805] “802511099 0188-1 
14 0.776 « | 0.823 a/ 9.141 8] 0.109'8| 0.259. b' | 0.226 hb! 
16 0.695 «| 90.789 «| 0.159 §/ 0.123 8} 0.286 h'; 0.250 al 
13 0.632 % | 0.669 a| OCL76 6 Oxise Bi OCS ato Ose cen? 
20 0.581 a | 0.615:«) 0.1946) 0.615096) OVess 0%) 0.294 -A! 
a2 0.533 4 | 0.569 a| §.c11 i) 0.164 °84'0.365 nl) °0.314 "8! 
04 0.504 a, | 0.536 «| 0.227 B | OVP 78 VO. S87 Oe sos ae 
Je) 0.474 0 | 0.499 a/ 0.243 p | 0.190 8 | 0.204 bh’ | 0.3857 a! 
28 0.448 aj 0.471 a] O.25u BY 0.2025 61.0.4 .erne U.sou a! 


~ 
~ 


ry weet €or Aw) 


30 0 6426:0 OO. 44 ae 0 v4 0.215 8 0.429 a' 0.8585 ob 

31 0.416.0°. 034395: a) (0.281840. 22t 8 Oey nue. Sos an 

32 0.407 as O2425 a0 289 (SiO .626 Ss 70. 444 ot 0.461 eh 

33 0.397 5a° 0.416 @ 70.6297 8" 0 6282.15 9/04 452 bl AD. 4038 h! 

54 0.8890 a 0406's. .00904-Bs O4 283 8 200460 A 70.416 hb? 

30 0.831 @)) 02898" 0.811.820 v24458 20467 20.220 1n! 
D326, Example 18. (figs. 202, 203). 


#or a factory floor as in Pig. 202, hollow blocks with seci- Heh 
ions 12 x 15 cm are used, 6 blocks to 1 m widto. Deaa + live 
joads = 640 kil/m?. Tnen for 2.5 m span the moment is:-- 

640 «x 2B x) 100 
v= ae fs eae = apout 40,000 cH ae 400 w aoe 
The effective depth a! (12 - 2) = 10 cm. Woat is tne required 
stsel section, and now great are the stresses oe steel and ~ 
tae olocks? . ! 
By tne Taple for n = 25 and o, = 1000 kil/cu? . (also see 237). 
10 = K #400, thus K = 0.500, 
a 1000 vos ( & an Se , Bite 5 ty 
Tnea oy the Taple for —3-- kilfjem*3,.0' 0.804 Jy aN 


Te = 0.227 /400 = 4:64 om? 
4.54 


i, = —--- = 0.76 cm? for a joint = 10 um (i, = 6 x 0.79 = 4,74 
2 ee Te EE SISAL SIR Si Secetiscl ttn cn Senet ee Sa AB oy ae a 
a pcr ees f° 200_¥ 40 ay cle ay ae a 
ie ciw) Serre carreras oni smtnenineiacsel Eat Aye 8h SE Saperecom bray arta es = e- ii _ ‘ % 
geet: “f 20) eye 74 : oS tees 

42 000 (ae i : 
Dn eo teacly ~ edt os temehe 4 < _Janpmeinge: ttc ieee ae marr. P74 = 24 j i 2 e 
“st eae < #53 (00 2 1. 33) eae 
49. 000 


Gs eee EY Ve tee 
© UF Fa RHO = 1o3) es fom 


Toe resistance oi the oricks must be at least:— 


24. %:100 
me-——=—— = 10 kil/cnu?. 
100 
val Rese oes of snear and pond stresses:—- 
640 x 2.5 m 
, e ert SU Mey eS | Cp) f —_ pr > iN 
Vues Ta ee B00 kil. bo, = 100 - 1% x 4.0 = 54 om. 
800 52ux 1.76_ 
Vo = ee 3 ee ee aS Le7d kil/cn?, Val tee one minaee = 4.85 k/ om? o 


52(10 - 1.23) 66. x 1.0 xT 
The steel roads are to pe firmly anchorea by dends at ends. 
NOL]? 1.23265. The hollow spaces here are each 4 cmH wide and 
WUst ve taken Unto account Wn the calculation of the shearing 
pases aes in the novsow bLOock floors. 
‘~“the moment if increased to 60,000 om kil, so that according 


278 
to Fig. 203 a covering layer of concrete 3 cm thick must be ft 
applied. Toen h!' = 15 - 2 = 13 cn. 
13 = K/600, thus K = 0.530. 


1000 
for ------=~. kil/ow?, f, = about 0.214 /600 = 5.25 cm. = 
26 to 2d 


— = §.58 ow? for a joint 11 mm thick. 
Section XV. Calculation of centrally loaded Supporis. 
a. Investigation for Compression. { 
It is first assumed, that the cross section of a support is 
f in cm?, and that no steel rods are tnerein. 1 then one has 
to do witn a single kina of structural material, wnicn experi- 
saces a shortening under a centrally acting load. Let tne for- 
ce oe P in kil, distributed uniformly over the entire area and 
with direction parallel to the longitudinal akis. If one now 
assumes, that the effect of this force P is exerted in pressing 
closer together the separate plane cross sections areas, and 
baat after the change of form tne cross sections remain with 
the same arrangement for each, then accoraing to tne statements 
on pe 227, 228:—— | 


ane | 
o, = 7 , and € = ora (mn == Asa tore ene 


Taus the elastic changes in length do not increase in the & 
same degree as the stresses. The moaucus of elasticity i, Oe 
according to Bach, variesp petween the iimits:-- 

& = 217 000 to 457 000 kil/cm?. 

Note Le Pod2Te By. Lhe builaring official tests and eencins vas 
ns of structural members under compression, Of tomped concrete 
(without revnforcement), according to the decree of the Pruss- 

pub, ais mca of Dec. 8, AZi10, ane BESO RNR SOE er a sae MICRA 
£ tae concrete supports oe now reinforced by steel rods, #. 
parallel to and symmetrically arranged about the Longitudinal 
axis, tnen tne compressile effect of the force P extends to 
bota the concrete cross section and also to the cross sections 
of the rods. Tae Longitudinal reinforcement must make the col- 
uwan safe against bending, since 1n consequence of tne required 
connection with tne beams, it may be exposed to pending stres- 
ses, particularly with very slended columns. It is assumed that 
tne steel participates in the change of form of the concrete. 
li the axial force P acts, then the shortenings of tne steel 
and tne concrete produced are equal 1ln consequence of the bona 


vag i 


‘ 
BOAO 
ae Ne 


resis tanc 


sea in di 


ad great. 


e of poth siructural materials (wnoen m = 1). 
o fe} 
Ey = So. thus es 
i, H 
D e 


=n, or in words:-~ since tne steel can offer n times 
& resistance to compression, 1t is only then compres- 
ke manner as the concrete if the force F is n times 
If a be inserted in tne formula, then results:-—— 


Thus potn for designing as well as for checking of a reinfor 
cea concrete support, the stress in the concrete is entirely 
aeterminative, + since tne stress in tne steel under an axially | 
acting load can néver attain the Otherwise allowable value for 
9, - Thus a strong reinforcement is not economical. Tae stren 


eth of tne columns cannot ve materially increased py bncreasi= 
og the main reinforcement. : 


Xote ie 


cApaAcVty 


ZS 


P. 323. Bxperiments nave shown, thot for the bearing 


of a column, a better wixture of concrete VWs nore ad= 


vantoageous. than an increase of the cross sectran of the \onér- 


SUaVaAahL rods With bAG Concrete. 


Note Ze 


1 3297 


4 . 


pe328. ALSO see Note 3 an pe. 330. 
is denoted the cross section of the compressed con- 


crete area, indeed witnout deduction of the relatively small 
cross section £, of tne steel, then the total stress in the o 


concrete 


botn stresses must dil ieeoe: the force P, so that:— «= 


and tne steel in consequence of the force P isi-- 
) 

P = Dy * Dei= Sn tp 8 8) Spite i: 

+ feriay 


SB Ohs el th vi (71) « 


ln 


Povee ens fe 


Note 1. 0.329. The value fy * nT, Tepresents NOTHING Ut the 


LOVGN ore 
steev Va 
CPOS8 8a 
AGCOrALe 
ony othe 
LOBn Ws 


Lnered 
20400 


s% section of the support, excepting that the total 
eultiplied by n, thus beings changed Vato a concrete 


Lvon Capaole of the same resistance as the concrete. 


\y o reinforced concrete support vs calcubLated LVke 


Suvport of homogeneous worterial, when one adds ther- 
s Lae seortvon of the steel. Nothiune can ve changed 


Lae wniforw Aistrioutron of the stress Vn the cross 


= f. = a Bak 


280 

if one desires to express f, in percentaye of the section of 
jas concrete, tnen are valid the following relations, waen £. 
22 peOwiee Be ta Io, and f, = pf, , 

Thus: Parity. top ips fy Ok CD Jane (72) « 
P (according to formula (70) BeOy = ot tlt pr open. 4073) 

but tae formula (70), as &xample 20 shows, may lead to unsu- 
itable results, indeed todnigh, thus to reinforcement percent- 
asjest not economical. Taat is then the case, if the supports -- 
oy important increase of tne longitudinal reinforcement = be 
wade a8 Slender as possible. i#xperiments of Bach have shown, 
tnat by increasing tne longitudinal reinforcement she breaking 
siréngta of tae support is not increased in tne degree to ve 
expectea from formula (70). The experiments proved, tnat a lon- 
Jitudinal reinforcement of 0.8 to 2.0 p-ce (at imost’ 2.5 pie.) 


© F530, 


Pp 


of tae concrete section (0.3 dor large and 2.0 for small, and 
sections under lesser stress) is most advisavle. = i 


Oné Can count on about <.0:p.c. if side h « 25 cm. 
1.0 p.c. 1f side n = 25 to 30 cm. 
1.0 p.c. if side b> 30 cu. | 


Note 1. 9.380. The Swiss Regulations give 0.6 pec. as the & 
Viet that can be cansidered for the reinforcement An colcula- 
LVAns. Purther see B & &. Volt ene. AQU. 

4itn too strong a epee 3 the rods will Fiat buckle : 
between tne Gross connections: tne crushing of the concrete = 
tnen follows later. Witn less reinforcement, tne Converse occ- 
urs: nere the steel is only Loaded after tne destruction of =p 
tne concrete. Very Lightly loaded columns receive a small relna- 
‘ormaewent only in view of any occurring pending moments. 

Toe Austrian Regulations contain the following rule:— If x 
vné area of the longitudinal rods is more than 2.0 p.c. of the — 
cntire area of tne cross section, then for the excess area of 
vac steel section over 42.0 p.ec., only one third part may be 
vaken in the calculation. * If the steel section amounts to .-~ 
less tnan 0.5 p.c. of the entire cross section, then is omitt- 
cd thé consideration of the steel rods in determining tne bear~ 
ing strenytn, and the compression member is to be calculated 
43 One of tamped concrete. 

NOV]? 2op-330~. According to the Howourd Regulations of 1913, 
Onby ane Walf the steel section in excess of 2 pec. may be ta- 


KON WH tae Calourlatitan. 


oO 

Hor the reinforcement round rods are almost exclusively emp- 
loyed, < especially if the adjacent floors and beams are rein- 
forced with rouna rods. 

NOUS? Se He350. A Vongituarinal reinforcement with angeles v3 
only aduisable for taller columns with regard to greater safe- 
vy GLanst buckling. For the cross connections are then best 
employed flats, which are connected with the angles vy rivet- 
vk to form a stiff skeleton. Such a steel skeletan Vs then a 
QOLE, Sven without an enclosure of concrete, to safely recevwe 
tae Loud of the upper centering and the dead werent of the i 
esh concrete floor. <= But as uch wore essential for g000 con-— 
structvon Ve the fact to ve resarded, that the effect of 1 kKAL 


oy steel Va bands -- in conarvtions otherwise similor -- is gen- 


erally cConsideraoly greater in reference to the vearing capac- 


Vy, than the effect of 1 Ki Vn the rods. See FZ & ae A2t1, ocr 
333, 4A2, 47%. ae 
for tne calculation of columns that extend through ‘covteate 
stories, tne following rules are taken in Pate etek 2 | cal— 
Sus er frow above downwards. i 
. [Increasing the cross section or ‘concrete. a 
- Raising the allowable compressile stress: frow 20 to 40 
(50) kii/fem?. (Seep. 207). 
o. neauction of percentage of longitudinal reinforcement ‘frou 
600 to OB bee. 
. Increasing the cross seinforcement. (See p. 355). 
#xample 19. (Fig. 205). ae at 
Calculation of columns extending through several stories wita 


Ziven loaas. LV: iil eo nee 
Story set ACECLC) 2 é .(Celiar) 

bhoad P = 10 tonnes. | 40 tonnes\.70 tonnes 110 tonnes. 
reG. p Of rein sape.0 peo. \ 1.6 pec. 1.2 ie Co 03 DeCe 
(i+np),form.(78) 1.30 Wes 4d 24 [ote Lele 
bllow.stress 0,=20 kil/cm? 27 kil/em? 34 ahh 40 kil/om? — 
fequired f, = 400 cm? |. 1200 em? | 1760 ou (2460 om? te 
concrete sect. 20°x520. = ie lSb' ios 42x 42 = 50 x 50 = 

400 om? | 1220 cw? |} 1760 cm? Hee cm? 
Steel section required = 
To = pip = 8.0 cm? | L9:.O%Cn* | 2165 2ont ()20 .4 cm? 
Actual St. sect 4 rods i6 a 4 rods of ‘26 mum = 21.24 cm? 

= $.04 om?. 


oO. Investigation of Buckling. 


236 
Wote L.peS3ie By formula (73): fy 


4 


Con AL a pays 


db. Investigation of Buckling. 
In the previous investigations any danger of Duckling was © 
excluaed. Tnis also occurs in columns of large cross section 
_ ana relatively small heignt. But if the percentage of steel 
het quite large, tnen the section of tne support will pve smali- 
er, and accordingly danger of puckling will be more easily pos= 
sipie. Yet this Ganger for compound supports is not so impor i-_ 
anv as for steel columns: as a rule for compound supporis it 
is unnecessary to prove oy calculation tne non-ekistence of 2 
any aganger from duckling. 

Tne Prussian nxcgulations prescribe that toe calculation of 
supports snall be wade against puckling, if tneir neignt be w& 
wore than 18 times tne least dimension of cross section, and 
toat for Gaiculation of supports for buckling #uler's formula 
snali oe employea. Pats 

Also rrofessor Thnuillle has proved boy experimenis, that for 
columns with heignts less than 18 times the least sectional @ 
dluwension, a special investigation for buckling is unnecessary. 

Tne generai prisciples state tne following:— 

Danger of buckling does not exist so long as the supports 
nave at Least the following dGisiensions:—— 

Stress in conérete in kil/cm?: 30 \ 35 )40402h 450\,50 
Least Gimension of side in 1/211 4/ 20) 1/15 1/18) 1/17. 
terms of nelignt: 

Toe Austrian Regulations:— for memoers in cowpression, Ssup= 
ports or parts of supports stressed py axial or excentric conm— 
pression, tne required resistance to buckling must oe taken = 
into account, 1f tne ratio of tne free iengin L to tne corres— 
bonding radius of gyration 1 of tne area of cross section 6éx- 
cseas the value SO of a 

fuler's formula for ouckling is (Wig. 206 b): t 


ii? 


(74). 

NOt] 1.9.332. The Tormutboa assumes a Winged fastening at each 
ena Of the wewoer, as shown in FIS. 206 b. But since the rerva- 
\OrGead Concrete supports are WOStLY SO Constructed, that one 
\Oy Statvcally regard then as fixed at voth ends, then with 


‘he use of the avoen forwurla, the factor of safetw ootarined is 


Mel ene 


2835 
much WVEhers for the bearing capacity Vs four times that for 
SUPports with Winged ends. In OV Cases WW simple burlartnes, 
(oa aa proce V = 0.68 L without danger, (See FIG. 206). 

‘For tne factor of safety s must = 10, according to official 
requirements. In tne calculation of the moment of inertia Taine 
ine Gross section of tne steel reinforcement is to be taken in 
ine Caleulations with its area x n:— 

2 2 
P= s5,(8) * Ip + Be * 1g) == yy (Ip +n Ig). 4 

NOV]? 1.0353. 10 VS Taken very High, see statements on p.206. 

If then one phages & = 143 000 kil/cm? (see p. 223), n = is, 
s = 10, expressing 1 in metres ana p in tonnes, omitting tne 
suaLl values of tne equatorial moments of inertia of theadiff— 


erent steel sections: 


(I, TLS Ee) =. 70h Boks C/E) 
Toe factor of sarety against buckling is tnoen:—— 
I 
iS} Nee pans on Hay 4 6 e 
oF Pra? G7S) 


According to experiments of letmajer, bauschinger and Conesi- 
aere, #uler's formula for duckling sives usable values only # 
ror memopers of sufficient length: for shorter lengthas toe for— 
wila loses its validity. Small excentric loads or flexure'of ~ 
ine axis of the wewoer may produce an important reduction of 
che oéf#naing loads. é UAE Elon te Sa 
Nove 2. podB3. Further see Zs B. 1910. p.185 24%. -- Zerits. 
of AVGN. We BHge 41912, NO. Sey abaol Zeltea. of Aust. nd. ull! 
ArGWe Unvonse AVL. No. 10. 
Tne Swiss Kkegulations require tne following:-- for slenaer 
columns and GOupression members, tne allowaple compressile si- 
ress O, with regard to pucks sie is to be odtainea oy the foru— 


UL @ Saas -—----2—~-~- . 


O:. = i 
x Ty Fo). OOG4y, (=) * 
i 
inere oO, = the otherwise allowable limit of stress (up to 
45 kil/om?}, = tne tree length in cu exposed to buckling, 


. = Least radius of gyration 1n Cui. 

“Tne Nurctempery Reyulations reguire:-—— the calculation of sup- 
vorts with regara to buckling 1s to be made by the following 
iormuula, if tneir neight exceeas 18 times tne least Giwension 
of tne cross section. + 

Note 1.pe33A4. Tne formula agrees with the fTorwula of the 


234 


: ye: 
VS placed = -. 
¥ 


Ye radvus of gyration of cross section). 


ieee On : 
o at Poe 
k ~ 4 + 0.0001 em 


Swiss Reeulatvons, vurt u 


According to MBrsca, if L = wathematical lengtn, and 1 = len- 
etn considered for puckling (see Fig. 206):— 

L for columns free at upper end. 
L for columns hinged at bota ends. 


i 


H 


0.7 L for columns hinged at top, fixed at pottom. 

= 0.5 Lb for columns fixed at pota ends. 

lt is further to pe investigated, woetner ine steel rods are 
. themselves also safe against puckling, © for tnese lie tolera- 
oly near tne exterior, and puckling would destroy tneir relai- 
ively thin concrete covering. Tne tensile resistance of tne 
concrete, tnat alone can offer resistance to puckling, is mucn 


mR Fe 
M 


t00 Swali to oe taken into account practically. Tne transverse 
connections (bandas) must then prevent tne ouckliny of the roas: 
out ab tne same time if tne closely set (spiral reinforcement), 
tnis increases the strengtn of the concrete, indeed by preven 
ting tne transverse expansion of the concrete. To be able to 
orevent sidewise flexure of tne longitudinal roads, must pdé made 
a firm connection of tne pands with the longitudinal roas oy 
wiring. : 

NOV]? ZeHe 3dh4~- Toe Austrian Regulatians state as folVows: -- 
In Compresston wmemoers the steel rods are abso to be examined 
separately WH Tegara to their resistance to bucking under the 
assumptrvon of a Length free to buckle ana equal to the distance 
apart of tne cross bands, the Latter are to be arranged art avVe- 
Vances at wost equal to the Least dvmensrian of the cross seot- 
pase of the compression wewmoer,. 

“fhe Prussian Regulations prescribe, that the distances pe tw- 
sen tae steel rods are to ve unalterably fixed by cross bands. 
Tae aistances petween these cross bands snall approximately 
correspond to tne least aimension of tne support, but shall » 
not exceed 380 times the diameter of tne Longitudinal rods. In 
tne calculation of the steel rods against buckling snali be. 
snown a fivefold safety. (But taese rules produce too great @ 
distances: see furtner below. 

Tne magnitude P containgbd in #uler's ronuaie for pucklinzg = 


23D 
in this case equals the cross section f, of one steel rod, wul- 
bipiled py the stress founa in tne steel, so thati-— 
iat 
Pp — 1 = ee 
[f Ll! = length for puckling of the member, tnus the distance 
apart of the transverse connections (Fig. 204), one finds by 
formula (74): .-- 
Lie O18 , (a and 1' in om and og in kil/cm*). (77). \ 
m4 , 


but the formula (77) nas no great practical value, Since it 
always gives too great distances. But the closer ins panas are 
Loyetner, SO much the greater will pe tne breaking Load. By & 
reaucing the distances apart of tne bands is optained a far 


zreater increase of tne bearing Capacity of the support, ‘than 


oy increasing tae Longitudinal reinforcement. Proper distances — 
are from 15 to 25 cm. One makes L' about = le times tne diame- 
ser of tne Longitudinal rods, or if on = siae of section of tne | 
support, l' =n = 5 cH, : aes es ae 
4 special calculation for buckling of tne steel roads py for— 
uulas (74) or (77). is then omitted. — Ree ee ce 
ine experiments of tne German Couwmission (Heft. 5, experime- 
ats on reinforcea concrete columns) 1 snoula aitford conclusions: 


D336. 


Coicerning the most suitable form of transverse reinforcement 
in reinforced concrete columns. Among otvner WU ERER « Cas exper 
lménats snaowsa>=—— ; ey 

Kote Lops BSSeb¥eo Bee Gomvesvas tnlO, Bie. Aaiaa ee oe 
1912, Pe 104, 105, 1913, peo 73, 24, 4914, 0. ate ever ean 
on columns etce., 3ee further B ann B, 1910, 9.376, A944, p98, 5, 
The 2044 4942, pe M20, (Ah@a AvM, Be 4G42, 9. 2hn) 07, Sahu 

a. That tne slipping of tne band, which always occurs in pr 
acvice, has no effect on the location of tne fracture, thus 
none on tne oreaking loaa: 


o. That tne effect of the different transverse reinforcements ae 


oa the peculiarities of tae resistance of the column is far 
oenedth tne effect of wore or less careful work in tawping tae 
COnNGrets. | 

c. That cross bands of simple rounds produce nigner resista- 
nce than crossed pands in loop form, tnat enclosing panas only 
Loucning tne steel rods near tne exterior of tne section (Fig. 
<Jd) generally nave better results than Qiazonal danas, ana # 
‘dat Compined transverse reinrorcement oy enclosing and dlago- 


230 
alagonal bands at tne same cross section nave a more unfavora= 
pbe effect than enclosing bands alone: (likewise the alternate 
1on of enclosing ana diagonal bands does not appear favoraple): 

a. That the grouping of several bands at tne same cross sec- 
tlon favors the occurrence of cracks. . 

for rectangular frames or especially large supports of floors 
way O& advisable alternating arrangements of bands as in Fig. 
208. 

c. Formulas for Designing. } 

In making a Gesign the following sequence of ideas is acter= 
winabtive: given 1s wostly tne load F in kil as well as ine hose 
igot L of the support in cm. On toe dasis of tne Prussian keg- 
ulations a cross section is chosen, that has a minimum side of 
kis cue (Calculation for puckling is then unnecessary). Tnen 


See formulas('70) ana (71). :— ' 


337 * 
{PG aes Si Poe tO en i | 
Be n oO D 8) re) ; 


Then take 6, = 20 to ~? kil/jicn*sn t= "15; andheor f. @ cross 
section with side h = ==: one then finds the required section 


Loe for 0, for example, 6, = 25 kil/cm?: 
18) . 
Bg Poy aa i? ele 
L ii Tae See = 376 - TE Sod Oe (LN Kite ho acm) s 
For 6, = 20 kil/fem?; f, = 3.385 P - 2.1 1? [| P in tonnes. 
17 ape 20, ee fo) =) 8.70 (Pisce 12) Jee (aoe 
+s) = Bone f.2 2.22 Boe.t 1%, ! lin metres. 


If one desires to economize concrete, tnen must the chosen 
steel sections are to pe correspondingly greater: conversely 
tné sectinal area f, 1s to pe increasea if economy in steel 
is to pe ootained. Toe less steel, the cneaper the support. & 
put formulas (80) may cause tne samc danger, tnat was men tion- 
sd on p. 529 concerning formula (70), particularly when tne & 
steel content 1s more than « p.c. If there be taken 5, = sO k 
kKil/cuw?, then as extreme values (P in tonnes): 


oh = 5 LO 5.5 JP \ 
a ° o >) P ( 2 cp ae 3 fi 
fe ty be fp /f for 2.0 to 0.8 p.c. reini't. (81) 
©” 50 100 J 


Tans cbear alstance petween external surface and steel is 2 
ville One may assume a = O.1 A. 
contrios. on &xperiments of Reinforcea Boncrete Commission 


237 | 
of Aust. Ing. u. Arco. Union (Heft 3). Tae pearing capacity of 
reinforced concrete columns is chisfly aependent on the quali- 
ty of. tae Concreie, Tne longitudinal reinforcement nas a unif- 
orm effect witnout regard to its ration to tae concrete section. 
n = 13 to 16 suffices for pressures up to 50 kil/cm?: for pig—. 
ner pressures, n sinks to 7.5 kil/cm?. (Pressure on Concrete 
040 kil/ow?). Transverse reinforcements, distant from each ot- 
er by more than the side of the cross section, show a reauc t— 
lon of tne strength of tas column. ven for jong columns(== 
23, wax dsflection i1 mm) destruction wostly results from ex- 
ceeding tne compressile resistance of the concrete, put only 
selaow oy buckling. * 

German Cosmission (Heft 21). The strengtn of reinforced col- 
ulnsS 1S Substantially increased by tne arrangement of neads. 

#xample ZO. Wig. 209. ; 

A concrete support of square section with siae of 26 cm is 

einforced oy 4 rods of 4.% cm diameter. Compression P = 
zo OOO kil. Height 1 of ‘support =1425 a. 

1. How great are the stresses in potn structural materials? 
Section area of support = f, = 267 = 676 ow?. eae 
Section are of reinforcement f, = 24.63 cm?. (See Table). 
Tnen according to formulas (70), (71), 

Dah = as OR ee = 24 kil/cm? 
G76) 4549 xy eae | 
0, = 15 x 24 = 360 kil/cm?. ; 

Tne stress found in tne concrete, according to the official 
regulations, corresponds to a crushing strengta of 10 x 24 = 
£40 kil/cm?. Witn a good mixture of concrete such a niga crusn— 
ing resistance is to be judged allowable, as well as the comp- 
ressile stress, in view of the very hign factor of safety. £ 


Note %epo 338. Furthernore Vn the corresponding Beaupre ot 
Vane of ficra\ resulaticns was obtained a crushing ‘strength of 
10 * 26.3 = 263. kitulow. 

6. Is toe support safe against ouckling? : 
Tne mowent of inertia of the cross section of the concrete 
is COmputed ati—— 


On See eG sean 
T, = —2= = == = 33031 con* 
d WW? Ys 


Ana the woment of inertia of tne reinforcehent ai:— 
A ERGs lal Ds Py | 
Tz5=4i--+fLe?]. * 
o4 


ano 


LOG 
NOUS Ze PedsBe {2 = sectvon ares of ane roa.” 


Ve = sectron of al\ rods. . 


ag wees Baas he Of inertia of tne sec tion of one rod 


a. ak yA 
4 


;30' Cu”, as sO. suall “in comparison | to 


i 
' 
; 
" 


a = 


av nei caacelLLeai— 


i A 1% Lath Ra ; 
e e* = 4 mane Ter 4) 105 ="24h63° ci* 4 


Thuswie = ger b 

4aiculation of the moment of inertia of a 

reCVTANBuUulLar BeCivah Ve aone in VVke Wanner. The axrvs of Is, 
naturally Vies parallel to the greater siace. 

‘ach i6 Calculated that force, that the support way recieves 
witnout danger of ouckliny oy fommula (75) :— 

(32,081.61). % 2463) = 7O.P x 4.54 
: P = 58 tonnes. 

Thus any danger of puckliny 1s excluaea, Since the existing 
axial force only amounts to gd tonnes. * 

Note 2. 0.339. ACTCOTALNE to the official reéuvations, Ln the 
Vs Example ON UWnvestrveation concerning ouckbiag would not art 
ov be necessary, since the hervaht of the support is Lass than 
13 tivwes the Least aAVmension of the section. The 1S har of s0- 
fety against ouckbing v3 oy formula Le)e-- 


38,084 * 15 * 2463 


3. Are tae rods safe against buckling? 

Since tne diameter a > 4.8 cm, and tne odbtainea stress in & 
ine steel o, = 360 kil/cm?, tne maximum distance between the 
required cross connections according tg Br. Prussian Regulati- 
ons is oy formula (77):-- L' = 518 x-— 

Such a distance pvetween pands is Buane too great. (See p. 335). 
One takes 1! = 26°= 5 = about. 20: tm, or Lb! = 22. x 2.8 =. 30 cus 

wxample cl. #xample of Designing. 
support 4 mw high is loadea py an axial compressile force 
kif. iné cross section is to be square, and 0, = 


76 cn. 


Ali/ Cm * ° 


i 


1. Take a = ==> = about 25 cm (thus fp = 625 cm?). Tnen oy 
sr 
OE ates SES i FO 2 

3 x 20 = 2.1 x 42 = 10.8 cm? = 4 rods of 2cO mm wita 

i, = 12.07 cu A 

; Be i Ara py tay 
(né reinforcewent thaus 18 100 x —=s=— = 2.0 p.c. 
625 
/ 


psig 20 000 a | 

6) formula 70 SL atte. elon ee sais a ee. = 20 E 4 

o (bY ) > Bae oii 512.57, es ledge 
(formula (81) gives the same result: h = 5 /20 = about 24.6 


kil/cm?. 


fF, = =z = 12.5 cm? = 4 rods of 20 mm.) 
= 50 | 


2e The side is to be only <0 cm. (Fig. 21-). One must f 
first count on a very strong reinforcement (> 2 p.c. le 


20 000 = SO x 400 | 
e. ea formula 78) = -—---------—---—— = 18 cm?, = 4 rods of 


15 x 30 
c4.um (£, = 18.08 cm?), a 
Reinforcement = 100 x et = 4.5 p.c.. (Thus a very uneconou- 
ical solutions). Sane | 


= SRB ee Ts TS RET ooo VI BT ROS = 30 ] 1 2% 
7b 7400 4 15 =18 008 kil cat, 


1: 
Toe column must be considerea for ouckling, since n < at 
3 2 i 


20 
T ==> + 15(4 x 4,58 x 72) = 26 600 cn*. 
factor of pafety. against puckling oy formula CPG yin. on ais acu 


s = f= = 77.8 /(thus.s >=:10). 


formula (75) finally shows wnat loaa P may be received by oa 
tne Column with the required safety: -- i Bi gee 
26 600 = 70 x P x 4%, thus P.= 23.8 tonnes. he eee a. | 
3. Tne side is to be SO cm, as in Fig. 212, -amaxaxkeinier- | | 
Prom investigation i it may oe decidea here (for Op = 30 rece: oor aaa 
/cuw?), that a pean of at wiost 0.3 pecs ae suffice. © | per es 
= 900 om. Ce ee GE, <. 
Horuula (78) snows Bs once, that a reinforcement 1s. not at 
all necessary for 0, = 50 kil/cm?: (P = Sp f5)= 20000. - 27000. 
P 34a eee leaner wixture ae SS & vhs W1bR Oy = | 20 kil/cu? A ro 
Taea oy formula (78), f, = SS Te ete = = 6.7 cm?. 
= 4 rods of 15 mw (f. = 3 85 Cin) 
4. Design 9y Tormula (81). Gowparison. 
P & PeCe reinforcement o OPS Dis O's reinforcement. 


nh = Sf 20" eee een = 352 /20 °3..20: cat. 

> tan 29 _ 00 a ae 

tes = = 10.6:6m? .=°4 rods ‘| 5 e 750 = 4.4 cm* = 4 rods 
fi 20 mm. (rods of 19 am of 16 mm. (rods of i2 um 
canngt. Bs used). abe $99. ere 


Ip = ser we een eee = \< =o 


529 + tO aes 57 : 625 + 1p x x 8, 8.04 
=28 kil/cm?. | ei LOM Me 


£90 
‘Seevion XVI. Calculation of excentrically stressed 
Supports and Arch Sections. 
It gas peen previously assumea, tnat the force P passes tar- 
ough tne centre of gravity of the area of tne cross section. 
If P now acts excentrically, then the edge of tne section lyi- 
ng nearest the force P will naturally oe more strongly compres— 
sed than tne other edge, whicn oy continued woviny P away fin- 
ally nas zero stress and then tensile stress. (As for supports 
of howogeneous material), it is to be determined by calculation, , 
wnether the point of application of the force lies within or 
outside of tne kern. + In the last case the existing tensile 
stresses are to ope received entirely by tne reinforcement. | 
Note 1. Pedh41. See Zerirts. Ff. Trefbooau. 1913. 9.82. (Garleurlart- 
von of the kern for a section of o column). 
4p eae compression comes @n Gonsideration for supports, 
‘oat are affected by pending by crane consoles or by strongly 
connectea girders. Then excentric compression occurs in bridge 
arches and stiff frame buildings (hall puildinys). Also see 
p. 182. 
The border of the kern is distant from every “gravity axis by 
= =f ‘on, if meee ne n(fi, + £4). W5 is tne moment of resis-— 
es of the section about the compressed side. Por an unsy um— 
etrical section (Fig. 218), for optainins the moment of resis- 
tance, tne location of the centre of gravity is first $e be on— 


tained indeed by tne relation:— 
n* 
me Oe if P t j a I 
ST nope S £EY Uh mat i] 


8S aeeeee----7----- = === ------ (82) 


bb p(t ek) 

The wouent of inertia of tne entire cross section apout the 
Jravity axis just found is tnen:—— “ 
ig = la + (n= 8)®] + nlfg(s - a)? + f4(h- 8 -al)2]. 
Kote Le Pe S42. The equatorial wowment of inertia of the sieer 
SeCCVONS are entirely unimportant for the caloulatian and are 
Wherefore onrvtteae 

or @ section symmetrical at both sides: 
Pls pie oe » andsa! = a. 


tor the symmetrical cross section that properly comes alone 
in COnsiageration for simple puildinys, the kern distance k is 


ae (83). 


i Foo 6 F a F 


cluaca. Tous the supports are to be so deslgnea, tnat their & 
naeignt is less than 18 times the least side of tne section (ac- 
cording to tae official requirements). Likewise tne cross pands 


are arrangea at distances of 12 times the diameter of the rods. = 


NOt]? Lee 3436 Soe Po 335- 
According to the location of tne point of application of P 
are to be distinguisnea two cases:—- i. F. acts within tne Kern: 
2, P acts outside the kern. 
Tne notation for tne formulas now to oe developed are:—- 
fF =pno +n (7g + f',) = total cross section in cu*. 
tes fi = cross gection of compressile reinforcement (fp, 
and of tensile reinforcement (f4 ). in ca. 
a, a' = distances of reinforcement fe oof Pr from tne con 
pression and tension sides in cu. 
k = kern distance in cm. (fo perimeter from cent.of gravity). 
excentricity in cw. (Distance of point of application 
of force P from tne centre of gravity of the canceese sect.i. 
= distance of zero line from compressed edge in cH. 


x 
is moment of inertia apout toe gravity axis in cu%t 
fo) 
0 


teri 
H} 


i) 


Ss : 
stress in concrete at compression side in kil/cm?. 


and 0, = stress in steel at tension side in kil/cn?. 


Oo, Of = stresses in stecl at tne compression and tension 
sides in kil/cm?. 
Toe value for e need not always oe given numerically. For P 
6 


- 100 tennes and M = 20 mw tonnes, for example, e = Spat 0.20 m. 
If P acts at the middle of the pier, but with Rap eaneteiee ar- 


ranyement of the reinforcement, then occurs excentric compres- 


a 


! 
A 
Br 


sile stresses. 
ae The point of application of P lies within tne kern.. 
Pigae only compressile stresses occur in the cross section: 
ine excentricity e < k, tne kern distance. The zero line will 
lie outsiae the cross section. (See Fig. 215 a). 

According to Fig. 218, conceive two forces P opposed in dir- 
section to pe applied, that will change nothing in tne equilib— 
rium. One then has to do witn an axially acting force P ana 
witn a couple P e, that is replacea by the moment M. - 


a Mon Se = yi 
Og = 4 Se jsrail bd (54) oe 


292 
Pe(n=8 


= ae we ae ew ee ee 


| (zy) 


Then tne stresses in the steel are to oe obtained as follows:- 
X~ a 


On 
afi: x = =— 2 (x- a), Ge = 0 Og -. 
By He x % 
fe) o} X- nota! 
Oty X= 83 (x— ih + ah), ob=0n 0g ——-tae—" 
ii fi . or x 
a) € 
| | is 
NOW Oat o am Otis (x - o), thus x = h —--"-—- 
Od ie o! 
[If tnis value for x pe inserted in the iwo first formulas, 
bnen results:-- | 
a (42a oe . 
Qa vt OT] (36). 


A omens! any, (87). 

Tae Limiting case is woen tne point of appt ican ion lies on 
tne perimeter of tne kern. Tans excentricity then = the kern & 
iasume x. For a symmetrical cross section, then:—— 

0g. = i + Taw = Tae e he (BB). 

But seldom will the case occur tnat P fails airectly on the 
oerimeter of tne kern, wherefore the formula for 9g will nave. 
only a small practical value. Yet one may thea caploy 1% also 
with advantage, wnen P acts tolerable near tne perimeter of ® 
ine kern, woetner inside or outsiae tne kern. The error in tine 
final result is but small. 

o. Ine point of application of P lies outside the kern. 

In the section occur compressile and tensile stresses. Toe 
sxcentricity e 1s greater than tne kern distance k. The zero 
line Lies witpjn tne cross section: tnus x < n. If P falls ex- 
actly on tne ;, then v = 0: if P lies outside the cross sec— 
tion, tnen v is negative. 

Then according to Fig. 215 c, if f, 
owing relations are establisned:—- 


at, the fol- 


i 
rh 


e ana a 


a : x= -~ . ( x ~- a) = — Pa ( h=-x- a) e 
i | ig the Be 
ha fe} oy See (89) 
b—4 n = a ee e . 
S re x gene 
Deer ee! ek x 
| ees ee ae a ee oe ae ° 
Fegan oa x ; (90) 
Oo xX 


Bb’ x 


+ Bte(e x - h)] (91). 


fq 


b x 
(X qi eS iP cree 8 tee Pots ey A Ee GN tn eraye 


for obtaining the distance x of the zero line there resulis 
frou the last equation after removal of the o-values the foll- 
owing relation: — 


el F -—— x? + (n+ 2 v)x = 2 a® + a®— alga +v). (92). 
By 
if the point of application of P lies wathin the section the 


joper Signs are valid: conversely if it lies outside the sect- 
‘on (for example with corbels), tnen sinee v beconeg minus, 2 
tne Lower signs are to ve taken. The solution of this equation 
Lhe thira degree is most conveniently obtained by trial cal- 

CHLavLons. . 

lf f, ana ff oave differen} values (f, > £4), and likewise 
a and a! (a > a’), then if rs be placed = a:—— 

H . € ; 
er. a ee a a 

- ¢ ala tv) etn 8) Car atere).. ery. 


If no compression reinforcement exists, then doth a and f hay. 


i + aon® (x - a) = Fees Ce ear 9 ui ae (24) 


i. ae; 


P S47 


As for making a design, generally toe foleewine) is to be st- 
atea;~= a 
Toe higaest allowable value for Og does nov always produce. 
sane section pest economically: it frequently is advisable to 
count on lower limiting stresses in the design. Both eer 
values for 0g and 0, can never be attained: Oo, seldom is over. 

500 to 600 kil/en? | : 

As a rule the dimensions of the conerete section are given, 
thus bo and bh. If P falls outside the kern, then one may employ 
toe following approximate calculation. . 

jitn the assumption of a homogeneous BPRS aoe material (w 

itaout reinforcement): 


- omy Coe ctag ba (95). 


Ona> = = = 
aCe fFoW bah p n2 bo 


me. —t (96) 6 
O>G fal : 
Since now the concrete cannot receive tensile stresses, tne 
-atire force % must pe transferred to tne reinforcement, thus: 


294 
ees 
Ce 

If og still lies within the allowable limits (55 = 40), then 
is inserted for o, the maximum value, tous 1000 or 1200 kil/cm2. 
But if one has obtained a higher value for o, (og > 40), then 
is taken a lower value for G,, for example 900 or 800 kil/cm?. 

In any case in checking, o, would becowe substantially lower, 
than was assumed in the design. But for Sq One optains an ent- 
irely usable value. Yet if 93 be still too great, then would 
either bh pe increased, or a compression reinforcement be eupl- 
oyed, which is better. 

In regard to the cakculation of excentrically stressed seci~ 
ions of supports, also see the literature concerned. 
ee duczowski, "Simplest method of dimengSioning tne cross sec— 
tions with excentrically applied. compressile or tensile forces." 
B and Z. 1911.p. 202, 247, 324. (With many calculated examples: 
Simple wetnod, also adapted for slaps and T-beaw shaped secti- 
ons of arcnes and frames). 

K. Stock, #Dimwensions of rectangular reinforced concrete sec- 
tions under axial compression and stressea for bending." Ari. 

6. 1911. p.388, 433.(Witn calculated examples and Taoles of « 
coefficients for o, = 1000 and 1200 kil/cm?). 

M. Mayer, ae ey of rectangular reinforced eonsraral 
ctions for combined resistance."Contribs. 1910, p.sgli« doit, 
iq 151, #51, 159. 

“? Nemec, B and #. 1914. p.43.(Simple approximate method) . 

Theini, "Calculating and Dimensioning of singly and doubly — 
reinforced sections, stressed by compression and bending. Gon- 
trios. i912. p. 94. 

Contribs. 1911, p. 150. (Teute method), p. 157. (Landmann's 
wethod for the case of equal reinforcement), p. 139, (Marcus! 
wethod for Tbeam section), 1913, p. 22, 30, 183. 

Band #, 1910. p. 66 (Sxample). ++ Arm. B. 1911, p. 227: 1913. . 
o. 24 (Rossin method): 1914, p. 19 (Nielsen method). + Clay 
Industries Journal, 1914. No 25. (Henkel method). 

Zeits. f£. Tiefoau. 1912,p.91, 104 (Example): 1911, p.31,45, 

95, 176, 192, 204: also B and #, 1913, p.9,358 (general inves- 
tigation of piers). 

On experiments with excentrically loaded Kovaaas. see "Research 
iork in tne domain of reinforced concrete:" Heft 10 (fhuillie's 
experiments): also Tauillie,"Further experiments with excen+ri 


i (ae 


295 | wipe 
excentricaily loaded reinforced concrete coluuns." further see 
Band #. i911. p.i52. (Witney experiments). | 

Example 22. (Figs. 216 to 219). . 
A support of reinforced concrete with the adjacent section 
is loaaed excentrically by a force P, anad:— 
i. P = 29 O00 kil with e 
é. P = 20 000 kil with e = 7.5 cm excentricity. 


hae P = 16 000 kil with e Fhe: QO om excentricity. 
i, 


4.0 cm excentricliy. 


Then F = 22 + 15 x 12.57 = ae cu? . 
I, = 25 + 16 x 12.57 x 197? = 267 4 gi* 
By formula (88) tae kern distance k = 7.5 Oil. 


1. P = 29 000 kil, e = 4.0 cu, iE etry inside the k 
ie 838) « 29 000 x 4.0 x 40 


remy = 24.9 kil 2. 004). 
i7aa~=—:=“ti ee 2B kil/ow?. (Form 24 
zg JOO 22: O00 'xt4 On a0 Eee ETE Se 

See re a ee ee ‘Toe ; 2. ‘Ty Sts i 
, mere Fe ETT | = 7.6 kii/cn (Form 8d) 
2439) =) 7 (by (40 18 ae ee 
o, ete (ee sah alae lA + 7.5] = 354 kil/om?. (86). 


pe Seeedl § PE ye see | a, Wa , AK ne: 
of = 16[ § ec aa a 437.615 = (142) ki hom? . (form.87). 


2. P = 20 000 kil, e = 7.5 cm, thus P falls on the peri 
ever of tne kern, 9’ = 0. (Pig. 218). 
2 * 20 000 


Og = mC EET = 26.4 kil/om?. ? (Formula 38). 
1/38 i: 
a 37 ati 4 | 
J, = 15 x 22.4 x RRs 811i kil/cw?. (Formula 86). | 
ae P = 16 000 kil, e¢ =.12 cm; so 'F falls ape of the kern. 


h ‘ 
v= 3 me Deel oe OD o | Wake 
So that P still lies in tne surface of the section. By forn— 
ula (92):— | ay ys 


~~ es ee pei ea A X74 24 x=) 2 85 O* HOLS Has 
Sx 15 x 12.56 15 x 12.56 | | 


x° - 24 x* + 389.12 x = 14 950;- x = 69.6 cu. 
By formula (91):-—- . 


16 600 %= Og ee + bags he (69.2 ~ 40], so Tq = 24.5 te 


aA 


Kll/om?. Se sh : . 
g = 10 * 24,5 x =i = 380 kil/ou®. (Form. 89). 
[1340 : 


ixample 23. (Pig. 220). 


Given the magnituaes: po = = 40 cn, a = 3 cn, Fo = 12.56 cu? 


hes bed cast neyl aenngegiayy 


tee 
ge 


Liye 


c =, ae a. 


Reson n = 50 cm, excentricity e = 40 cm. 
os we Gp, 347) is eed ae! what steel 


nL ST 
“es 


oi 


ioe 
ar earn 5c 3 (1 + 4 3). 
= 46.4 ‘kil/ ca? Pouprensiany and 


oy ‘kil/ om? tension. 


a x i) = 19. 3 Cli. 


30.4 x 19.3 = 15 048 wad 2 | 
uply large, 9, is made = 900 (instead of 


~=-— = 16.7 cw? = 4 rods of 24 am. 


297 
Section XVII. Spirally panded concrete. 

Recently for concrete structures are frequently employed coi— 
umans Of spirally banded concrete, according to a metnod given 
ror them by Considere, which has the advantage of particular 
slenderness. A single continuous spiral encloses the concrete. 
nucleus,and produces an increase of 2 to 3 timwesin the support= 
ing Capacity in comparison with columns, tnat contain an equal 
amount of steel in tne form of longitudinal roads. Toe spiral 
oanding aiso allows yreater stresses in the steel: it further. 
prevents displacement of the pands pb: tamping. (Also see Fig. 
51, gp. 131). Ordinary bands indeed protect the longitudinal # 
rods Irom buckling, but increase tne resistance of the concre- 
te in a very small degree. Furtner advantayes are seen on p. 
oo2 under 1 and 2. 

Tne metnoa of. calculation of spiral bands is fixed py tne 
prussian Ministry of Public Works py the decree of Sept. 13, 


Let RS = total section of tne concrete. 
P. = total section of vertical sieel rods. 
0367 pee section of an ideal vertical reinforcement, if tne 


sveel existing in tas spiral band per unit of column be trans— 
formed into a longitudinal reinforcement of the same dength © 
with equal volume. 

Then tne ideal section of tne column tnus formea is:— 


; fi | (97). 
Tne allowable P for tas column 18 determined o::—— 
(98). 


; 2 
In whicn 0, denotes ine aliowaple compressiie stress in tne 
concrete of tne support, accoraing to tne existing regulations. 
ine harger section f, resuiting from tae formula, however is. 
only peruititead so lon, 4s 1t does not exceed 2 Hp. (Fy so Bo) 
see txanple 24, p. 353, taken from the official requirewenis. 
In @ .ater decree (liec. 21, 1309), it is stated that tne pro- 


vsdure in Calculation in structures does not aLons depend on 


Lvnsiagers's treatment, cui likewise on other spiral transverse 
Colnicoseémeont, navine the same effect on the bearing capacity 


Ol the celinatforced concrete. 
To sal 1de¢a of such a spiral reinforcemeni consists in > 
uné inc cease Of the strength by the addition of spirals, tnat 


prevent or delay the formation of slip surfaces. 1 the section 


oi tas Luna is mostly round or octagonal,also aexagonal, al 


4 298 
ee only in the Avranawoff-Yagida mode of spiral banding. 
(See p. 506). Toe spirals as a rule are aelivered at the buil- 
ding site ready for use, They are made in the worksaop by win- 
ailing at a turnigy latoe a straight roa around a hollow steel 
me that may de round or polyyonal. 1 after the form nas 
cen waas 1 m Alga, tne vertical rods are set,ana in the pres-— 
crloed manner,are Connected py wiring With a spiral 1 m nign. 
Tois is tnen tagped, a new spiral of i w is placea ana ine 
formu is extended to correspond. To obtain a safe butt conneci-. 
ion of the spirals, each laps for two or three turns. 

Nove Lepe351. The destruction of a concrete prism oy compres- 
van Vs generalky Bu the formation of slip surfaces, on which 
the shearing resistance is overcome. ! 

Note 1.p.352. On winding machines, Bee B & B, 19:2, p.35.. 

Toe chief advantages of spiral banding are the following: Say) 

Ll. Proauction of a small section of tne column. | 
for example, 1f P = 4009 tonnes, o, = SO kii/cm*, then the sup= r. 
pore with the ordinary dands wits SD .Cie reinforcement of tae 

ast section is_computed at:— 


F he ee 
CF een (See formuis #0), thus 
P 4090 000 , hee 
Pe eee FS er ee O00 ca = 9G "be cH. 
30). % £343 es Rite 
By spiral oanding (0, = 35 kil/cm?) under similar conditions 
and accoraing to the official resulations:—— 
P 400 900) +2 . 
By = tooma-s = === = 87 000 om? = 78 x 15 cm. 
ae Shr ate are ne i | 
z. Use of Less steel for given dimensions of the support. 


For example, for a cellar pier, P = 300 tonnes, o, = 30 kil/cu?, 
bnen with an ordinary banded support 85 x 85 cm, tne steel sec- 
tion {according to formula 76) isi--, : 3 ass 
p, = atte a Bis ey = epee one el ee coe 
SO oy 7 sO «35 , oe 
Longitudinal reinforcemsnt at RA: Ace of Fy = = phim cu. 


pa. . ral me 
300 000 ~ 30s eee a 


By formula (76) fF, = -+--+----—----—--—— = 135 cm2. 

: ee G 15 x #0 

Adding about 10 cm? for ordinary bands = _j10 
Total 195 cm?. 


nit tae upper stories tne difference is smaller. 
From the previous experiments with spirally panded coluans 
way oe deduced the following principées. 


299 

Kote 1. ped53. See RSrack and others, “Bxperiments with corl- 
UBRS GAG Taerty caluclatron.” Gontrrios. 1912. p.101, 105, KLein- 
LVoget, “Galearlation of spirally banded cancrete.” Yontrios. 1 
1902, pe AT. ts Bp 

Toe total reinforcement (longitudinal rods and spiral) must 
not be under 1.5 nor over 8.0 p.c. of the cross section. Only 
concentrically arranged or spirals witnin each otner may exceed 
this maximum value. : . | 

The ratio of longitudinal to spiral reinforcement (F, . p 
wust-amoust. to-1 272 to Jy: 3.72 


ey, 
fo) 

Note 2.pedd3~. TOO strong © Longitudinal rernforcenent VS Use- 
\ess, since the sieos Vn the spiral to utilized twice vertter 
LAaNn THAT VA the Voneritudrinar roads. 

Tae ravio of thé rise of spiral to diameter of section tsa) 
D in Fig 223) must be with average spiral reinforcement (up to 
2 peGa) BOONE T/T oto 1/G, "for, Bree tee V8! bo). 4/26 (mint val- 
us is 1/5). 

Spirals of smaller rods with closer turns are nore effecient 
for the same steel used, than those with larger rods and wore 
open turns. The effect of tas spiral bnen first begins woen ia 
tne concrete is so niga, that 1ts own resistance | is exceeaed. 

for tne calculation of the oreaking strenag ta is used only 
tne internal concrete, since naturally the snell outsiae tne 
spiral first preaks off. After tne occurrence of the first 
cracks in the snell the spirally panded conorete can yet susi- 
ain considerable loads: fracture does not follow suddenly, wa- 
ile for concrete only reinforced lengthwise, the Ogcurtrence of 
tne first: indications of breaking is sson followsa Py. entire 
ages traction. 

Yet Considere's kina of spiral, protected by patent, does. Se 
not alone exert a favorable influence on tne resistance of con- 
crete to compression. Experiments have shown, thai a spiral = 
reinforcement has no better effect than a sufficient number of 


P37%, 


annular bandas. 4 Yet closely set separate bands put rarely ea¢ 
ust spiral banding in CalGule teks colefly indeed since in tan- 
ping the numerous separate bands do not retain equal distances 
apart, and are occasionally displaced: all calculation of ban- 
ding must then oe doubtirul. | 

Note 1. p.3d4- Bxperiments of the Gross-Lichtenfelde ywaterr- 
ols Testing Lavoratory hove shown, that the ordinary ring rein- 


{or@ement indeed Leads to fracture somewhat earlier than with, 


pelts 
aig ‘i wis 


ea 


300 

Sprral vanding. -- AVSO see the experiments of Kveinvogel, Con- 
VV VOS. 19142, P.-33, AG. 

ihat concerns toe purely economical side of spirally banded 
concreis, ths saving 1n concrete, and in Longitudinel rods is 
opposed to tne use of 5 to & times as much steel for banding 
tne external surface, that also makes more difficult a good +. 
taping of tne concretes tne concrete must de used as wet as 
possible. < 

Nove 2. Pe-354. Unfortunate for spirally banded concrete is 
also the fact, that Vn practice in general, no structural nen- 
vers are tO be Made, that are constantly subject to the waxiu- 
um Voads, out rather wewoers, that are able to receive the in- 
Venaed Voads with the prescribed safety. 

Kleiniogel 3 nas suygested a formula: P = fe x Ky + 2400 x 

+ 2.4 HL), in wolcn: += | 

f),, = cross section of the concrete inside the banding. 
Ky = strénxia of the concrete, 4 160 °t0''220 kii/om?? 
Note 3. p.-354. See Sontribu. 1909, p.47: Avm B, 1913,0.370. 
Note 4.p-so4. One wust not assume the value of Ky Buch HLEh- 


(# 


=~ 
— 
ww 


evr, StNGe WH Consequence Of the spiral oanding of the Vonerviu- 
ana roas, the tawping cannot ve as unifora as for the usual 
reinforcement. | 

Another formula nas doesn given by warsea,? indeed on the gr/- 
ouna of experimenis on columns oy tne Reinforced Concrete Con 
wission of tne Jupilee Foundation of German Industry (Contribs. 
on Reasearca Work, neft 63), the sxperimenis of the Wayss and 
fireytagy Co in the years 1905 and 1910, tne experiments on col- 
uahs py tae Freaco Commission, and ihe experiments of tne Ger- 
wan Commission on reinforced concrete columns. | 

Toe formula runs:-- 

PR Oats Bek a ke Pe 

oO. = elastic limit of the longitudinal rods (2400 to 2800 
kil/om?). | 

mn Ky = 3000 to 7500 (corresponding to k, = 160 to 220 kii/cm?). 

Note 5.p-354. See Contrivs. 1912. p.-101, 105). 

According to tns experiments of MBrscn the spiral banding is 
sotirely without effect for squars columns: out for round col- 
uuns 153 it more plainly useful. 6 
9,3 hore GepeSdhe Soe B& Be 1943, pe 67. 
Austrian Kegulations: Hor compound members, where besides 


Longitudinal rods also spirally wound continuous transverse 


301 
reinforcement is arrangea, for determining the compressile si- 
ress in consequence of axial compression, is to pe introaucea 
an jaeal section area:-—- 
Po SePyor 1B Went 30 FS 
Hf, = toe entire corss section of ths concrete. 


. Ln whica:-- 


Ho = tas secbional ares of tne longitudinal rods (under con— 
slaeration of tne special aétermination of tae Austrian kegul- 
ations, given on p. 330). 

DP tas sectional area of a conceived Longitudinal reinfor- 
Gewent, waose weight = vhat of the spiral reinforcement, both 
welghats peling Btn | tile to tne unit of Length of tne compressi- 
on wembder. 

Toe ideal area thus formed naere 1si-- 

Fo erd.O (P+ 15 8. a) Obvee.0 Pre 
Toen for Fj wust pe taken in consideration only ine swaller. 
of taese two limiting values. For excentric Loading toe spiral 
reinforcement is not to oe taken into account for ootaining 
e stresses resulting from tne pending woucat., Tne distance 
ostween turns Of she spiral way at most de 1/5 of tne least a 
diameter drawn tarougn tae centre of gravity of tne section. 

Compression members witno longitudinal reinforcement ana such 

transverse reinforcement or arrangements, waich in this effect 


ad 


equala spirally wound continuous transverse reinforcement, are 
Likewise to be calculated in the precédiny sense. Oe 
Nurtempery Regulations: If oy ey cross connections (ring, 
spiral or sisilar enclosures), a Soiral banding of tne concrs-— 
te ls proauced, tnen for tne distance between turns of the sp- 
iral or between the rings, the ratio@ to tne diameter of tne 
ternal section must oe Less than 1/5. Toe aklowadle load on 
spirally oanded columns is:- $ 
Py = Op (fF, + 15 PF euh. 43 Fi). 
dere F, =; internal area of concrete section | 
do, = allowadle stress in concrete for calumns. 
iamburg Regulations of tne year 1913: tae presicridea formu= 
la isi—-  P = 6) LF, + io (Fy + a PERS RcO nis phat 
hgh 95 = 35 kil/cm?, Pi Z ra Fo: 7 
for spiral banding by Apranamoff+ Magid metnod. 
uw = 2 for spiral banding according to Considere witn turns 
at wost = 1/5 of diameter of tas steel spiral. 
Swiss Regulations: If tne transverse connections form trus 


spirals at neignis of not over 1/5 the diameter, 


mi 


MURS! 


. 302 
24 times tne volume of tne Longitudinal reinforcement of equal 
volume 18 to oe taken into account as participating in the con- 
pression. Tne ideal cross ssction must not excesd twice tne 
section of thec Concrete. 

for spirally oanded columns, tne number 24 py wnich tne sac- 
tion of a straignt rod of equal volume is to be multiplied, is 
inat estaplisnea py Considere: only tne spiral rods wita d1st— 
ances not over 1/5 the diameter of the column are effective. 
Tne relation is #) = BF) + n( Fy + 2.4 FL), when n = 10. 

Spécial advantases may be offered by spiral bandang according 
co tae métnoa of Abranamoff-hmayid. i Tae reinforcement here 8 
consists of separate [lats, tnat correspond to ths sides of q 
tne Support to o¢ formed, bdelng connected together by the lon- 
situdinal roas.(FPig. 226). Tae production of the spiral flats 
proceeds rapialy. Fig. 224 snows a aevelopea spiral (convenient 
to send to Bae Dullding site), Hig. 225 1s a spiral drawn out 
io tae required rate of rise. The reinforcement suits every € 
form of column, even the square: ii always lies at the outer 
oF rface, and thus encloses a maximum concrete se ction. 1 for 
| ‘dis reason it is also particularly Sulivea for reinforcement 
of concrete beams as in Fig. 227. 6 

Note 1. p.357. Ane must endeavor to enlarge the vanded cage 
crete aS much as possriole. Unfortunately the Prussian Regula- 
LIONS BO NOD GVSTINGUrtLsh Hetween the enclosed concrete and | 
the external concrete snetl, out take into the calculation the 
entree conerete Section, without regard to the Location of the 
SoVraby vbandind. Tn a dveaking conditrvan there remains of the 
Concrete sectr1on only the enclosea cancrerte. 

KOtS] 2. H-B57. Further see B& H, LAL, P.Al14, 429. Rewarka-— 
ye Ve the use of an Avdromoff-Madid spiral banding for a pipe 

Ltn & GAtLwospheres Vnternal pressure and a ckhear OV GRG LET BAN 
2.2 We (Contrios. 1943. p. 42)e 

Decree of Feb. vy, 4912, concerning the calculation of reini-_ 

rete beams witn wore spirals inserted in the compres- 


<The reinforcement of reinforced concrete with inlaid wire 
spirals or similar coiis, first permitted for columns by the # 
Lormer aecreé, Gan also oe used without hesitation for streng- 
Liening the compression zone of reinforced concrete beans. Al- 
50 ine calculation of suca reinforced beans may follow the me- 
10as given for calumns in ihs decree of Sept. 12, 190% 


Ne rer easmencgeeater mninel inet 


303 
[ae coupressile stress in concrete assumed for this calculation 
way be obtained in this manner, that the maximum extreme stress 
in tne concrete, that according io the usual mode of calculat~ 
ion for reinforced concrete beams, that neglects the steel re- 
inforcement ln thé compression gone, will pe wultiplied ty the 
area Of tne enclosea cross section." 

Tnus 1t first snall oe computed as if no compression roas éx- 
lsted: the compressile stress in tne concrete assumed for fur- 
taer Calculations is then placed equal to the proauct of the 
maximum stress al edge py tne englosed portion of the area, in 
order finally to calculate according to the preceding rules ¥ 
for spirally reinforced concrete. See kxample 26. 5 

Note 3. pe35d7. ALSO see Preuss, “Beams with spriro\ly rerivnfor- 

4 re ERKRMRKRSXXSERXEXRREKE COMPTession zone.” B & B, 1913.9.54. 
'~""fo this decree is appended tne following dalculated ees 
(Centsias.Bauv. 1912. No. i7:— P 

Given, negative woment M = — 1 000 000 cw kil. Tension rein— 
forcement 6 rods of 22 wm diameter (22.81 cm®): compression = 
reinforcement 4 rods of 16 wm (8,04 cm?), as well as a rectan- 
sular pent wire spiral of 7 um diameter().33 om?) 25 OM high 


with 4 com pe € turns. rae GG 
TS ay St ee je , 28 50% 61.9 eo ce 
SBases / id x mish Me 
Z i 900 9000 
on = ~-=#-—=-= 5-5 5 = 61.61 kii/cu*. 


80 x 24.8 [51.9 TRE YA | 


This compressile stress is assumed to be uniformly distriou- 
tea over tne enclosed sectional area of tne dean, 
P = 30 x 25 x 61.61 = Ss 200 .% | 
B= 20 |* 30. = 
for i m length of beam 


F 


i Be x 4 x 0.25 * 0.383 = 9.6 Cuts 


F, = 750 + 15 x 3.04 + ey. 9.5 = 1156 cu? 


op = P = poe a 40 kal/ cm? . 
f,: 14456 


iixample 24. ‘ 
Note 1. 9.358. Taken from Brussian Regulations, Puo. We. Beast. 
A column of 45 om diameter and F, = 1590 cm? nas 6 longitud- 
inal rods of 2 cm diameter, or F, = 6 x 3.14 = 18.84 com*. Tae 
spiral reinforcement sxtending around tne longitudinal rods ior 
40 cm diameter of the spiral rings nas per m in nelgnt cv steel 


Bias Pg : 


304 
rings of 1.4 cm diameter and F,= 154 cm*, so tnat for the m in - 
neigot, FL py the equation gives:— | | 
#2 #1 .08= 00% 3.14 °* 0.40 x 1.54 = 38268 cat. 
{nerefore:—— 
F, = S09Gcs 15 x 18.84 .+ 30 x 38.63 = 3033 cm? < 2 x 1590 = 
3180 cm? 
if the test cube has a crushing resistance of 200 kil/cu?, 
585" is taere an allowable compressile stress in the column of 
“~= = 20 kil/cw?, and taus a permissible loading of the column, 
34. of P = 20 x 3.085 = 60.7 tonnes. 
Resistance to puckling is found py the existing rules. 
Bxauple 25. (#xauple of designing( Figs. 229, 200. 
A support has to carry a live load of 250 — kil. 


P _ 250 400 eee ee 
ty gigs Tota = 7156 ie ee 


With 0.5 p.c.. of FP, for tne longitudinal rods and 0.7 pc = 
of F, for the spiral rods, tne required concrete cross section 


i} 
OS 
O> 
(aw) 
on 


is. 5 fa ary i a ST 
Fo = rat: pia eee an ee oan = 75 x 75 om.(fp 


= 0.005 x 5625 = £8.13 cm* = 4 rods of 26 wm = 21.24 
; ~4 rods of 15 an ELOY: 
#,7fnPont 2°" ~ aotet 
Then is found per lineal mw of Lubbers the required total geC— 
tion of tne spiral reinforcement at :— Lats 


BAe H pi 1 giz ie Cat Ase ' a , 
Flos sr ee rs Sta a ee = 36.84. aS 


r=) 
@ 
H 


Ghosen for tne spiral reinforcement (systeu Abramamoff > lagi). 
are rods of 8 mm diameter witn.13 turns per m: then is ae, 
PE 4 xe x ex WAS gu et 
Here 4 denotes tae four sides of the square. a ia 
= lengta of spiral between 6 longitudinal rods e ae 
w = no. of turns per lineal m of support. 
fL # section of spiral reiniorcement.— 
D360 Tae Lengtn e is found as follows;—- 


Gy - 2 
SS BVGIle eget a 


e = pb ~ Coyxrese 
isre 0 denotes the side of the square. 
d, = diameter of spiral rod. 
d. = diameter of ae pee bear: 


2 
Pie 4&2 OCT Xx 182% 0Ne = 6.92 cm*. 


Ms 


San 
Ra tasaie 
wa 


set 


ae 


ee 


ao P Cee ai ____250 400 400 

DFO") 16 F,.* 30 F, 5625 + 16 « 0.81 ¥ sO «x 6.98) 
kil/ om? 

Hxample 26. (Fig. 231). | 

According to Fig. 2ol , the moment of peam at a support is 

- 20 000 wm kil. nh = 70 cm, h' = G5 cm, and pb, = 40 cm. 
Tensile reinforcement f, = 46.382 cm* 
{nen by formulas (5) to (7) are found:— 
X = 33.37 cu, 0) = 69.2 kil/cm?, and o, = 990 kil/cm?. 

To reduce tne stress in the Concrete to tas allowable limit 
alue of o, = 40 kil/cn*, the oversiressed part of the compres- 
slon gone is strengthened by spiral reinforcement. According 
to tne Fig. the nelght of tais portion is :— 


6, — 40 69.2 ='40 | ie 
g! = -Q-—--- x x, = --------= x 33.37%°= aot 16 om. 
35 Od 66 


Assuming a uniform distribution of the eage stress over ine 
enclosea part of tne section, the compressile force in this = 
portion is: P = s'b, op) = 15 x 40 x 69.2 = 42 000 kil. 


a Pde OOD aae ann 
o> io tea a ate f ; 
p.3b/ Foe el Ds = dae ™ 40) =) GOO ime Ce 3 ee ay Mae 
longitudinal rods: F, = 0.5 p.c. of By, = 0.005 x 0 = ikea 
= 4 rods of 10 wm,(3.14 cm?). ' 


i 


Poo= 415 F 1050 - & 
Splral reinforcement: Fi = Fy Bp 2 48. Be am 4000, 600 1d 


SR) a ake ee oo ore 


30 


a 


x $,14 = 13.43 cm*. 

Caosen are rods of & mm witn ff = 0.50 cm?: no. of turns per 
lineal w,: w = 12.5 turns. 7 i » 
PL = o42 a! +2 o)fs w = 2(2'x 15 +62%40)*.0.6°%, 12.6. = 13476 
ona Pa 42 000 be | 
ois H+ GR, | eo edie ao fo ee 

Toe spiral ceineaecesene 1s according to tne system of Abra- 
namofi=Magid. The shears are obtained in tne usual manner and 
are so received. 

Spiral Reinforcement of Gast [ron, Hmperger System. 

For spirally reinforced concrete, tae spirals increase ine 
resistance of the internal concrete to compression: on the con- 
trary for spirally reinforced cast iron tiney indeed safely re- 
taln the concret covering of the cast iron until fracture, tnus 
aiding in preventing this from separating. Aside from protect- 
lon fTrow fire and rust, the concrete combines the separate cast 


ir 
ad athe 
Jeon foes 


AUT 3 
EM raia len 


ee ae ah 
Semper oe 


san f 
ffige se see 


Se 
& 


306 

portions together, and witn its steel spiral panding makes the 
brittle cast 1lron elastic and flexiple, increases the section 
of tne support, and ensures a statical cooperation of the ent 
ire cross section up to breaking. In tne experiments appeared 
at fracture an ¢ntirely elastic benavion: tne changes in forn. 
produced py the Loading returnea again to wero. With a consid- 
erable increase of tae bearing capacity, one nas the advantage 
of @ small section of toe member, tous a great slenderness of 
bhe Compression member (columns). Notable is ine following com 
parison of different round columns, on tne oasis of a total & 
loaa of 265 tonnes. 

Note 1.p-361. Further see emperder, "Recent arched oriades 
of spirally banded cast iron,” as well as B & B, 12912, » 35%, 
116; 19143, p.34, 137, 365, “The Foundry,” 1944, Rett 5, 6 LT 
("Bxpermients on allowaole Loads on sabe beef es pe Pat ibeg pS a hpbelt 


‘ 


cast Vron®). | retiree scnanat ts \ concrete | 
Area of section °0.13 m?\°O.50 mw? "0.70 m2 
Goncrete per lin. un. O40. 0540.50.) a4 O.70 m? 
Steel 1n rods ana spirais | : 
per mw lineal 18 kil |172 kil des kil 
Cast Iron, per w lineal. 130 kil |! ¢¢/-4-—- _----- 


OMISSION. 
Un page 203 of this translation (page 242 of tne original) 
paragraph > was omitted., ana is elven here 


>. Ine Table relates to plates witn b= 1.0 n wigtn ‘for cal- 


Calation. For designing the moment ki is to be inserted in hk kil 
for obtaining the stres in cm kil.(88e wxample 1. Pe 246). The 
lable may likewise be employea for T—peans indéed, if tne zero 
iiné falis in the cross section of the slab. (See Section x). 


yeviett pe 
ye 


' 


807 


PARE Pegi ae od ep +" Reinforced Goncrete. 
atio o russian enera Wurtember lati 
Moduii of Regulations Prins. ,Re slaneawe Austrian Regulations 
Blasticit:. 1907 German 1913 1 19tt. 

Concrete 

‘Union 

1904 
a @ 

Ratio of 


Moduluses of 
Blasticit: 


Baca i5 15 15 15 

Flexure. | ; ; 

Compressile 1/6 the 49 to 40 (30) 42 witn 470 k cement 
stress 0, resistance 50 (lixewise for 37 with 350 & cem. 
ing to | excentric 32 wito 280 k Cem. 
kil’ /en* crusaing compression) per m3, 


same for ¢xcentric 
compression). 6% 


bh = a SOPYSi¢ensile ~~~ Por 6xeentrie 5 with 470k eons’ 
Oo. in resistance gone erat. at24 with 350 k cem. 
kil/en? OF 1/10 tae sage 6 (4). 22 witno 380 k cem. 
crusaing per m> ; ; 
resistance . (Same for sexeentric 
aes is - compression). 
Shearing, 4.5 k/cm 4.5 4 (3) Values 4.5 witn 470 k cem. 
stress, To,0rl 7. res- 4,0 wita 350 k cem. 
in kil /om*istances to ia 3.5 with,280 k cem. . 
» sSnpearing. per m®° AB an 
> ee we ‘etiaee ~ : Orackéis Bg Be yates an 
ache Pe a Ta trite Mire 4 (3) : (5.3 wita 470 k cam. 
418 kil / for 5.0 with 350 k com.) 
em heavy 4.5 witno 280 k com. 
shocks. per a, re Seen 
Gompressile 1/10 the 35,0 36 (27) 28 with 470 k cem, — 
Stress 10 opyushing 35 wita 350 k cem, 
SUB POR Ena a are 22 with £80 k cem, 
p 2a F te 
kil /em® 
Tensile and 1000 and 1000 fo LOOT F564 1000 
coppressile 1200 and more (feast ten- 
stress in (Decree of Sile resist-=- 
mild steel mae a) ance =',3800 
Oo, in 313. kil /om*. 
Notes: reyiivga  ‘Requir’d Required Required least crusa- 
2 Bas o/ least .. least | ing registance =! 17 
esyusadu 3 crusnaing crushing kil/cm*for 470 kil cem. 
‘g5°sys oc epesistance resistance 150 kil/com® for 350, 
SPRUNG. 8h TBO) OOO Le i eae COMSa ke 130 kil’/ 
500 Ai dyoia* cary cope erg th og ae Bera Cem. . 
dL YOR BN, af tg att or mn amped con= 
ways. caf s* aby8° crete (after 6 weeks). | 


Note 1.p.224. Coasiaering tae variations of temperature tne all- 
owable stresses Will be exceeded about 1/3, and apout 1/2, if the 
snvpinkage be consiaered at tae Same time (fall up to 15°C. 
Note2.p.224. Tae lower Limit 1s to be taken, if tne alam. of the 
longitudinal roas *=/ 1/10 ieast aimension of the structural member, 
and the Gist. bet. cross reinforcement corresponds to tois, dimen. 
Toe upper limit is taken if ths diam. of tae rods =! only 1/20 of 
least sectional dimension, and dist. bet cross reinforcement am-. 
oumts to 1/38 this aimension. ; 


‘aaah 
Dees) Huy 


pyri; 


bees 
th pak aap 
, ud 


4 ' 308 
LEG Allowaole Stresses in Reinformed Concrete. 
Frenca | Engiisa Swiss Regulations. Hungarian 
Regulations. Regulations e Regulations 
1906. 1907, (swiss Gommission on . ‘ 
Reinforced Concrete).( Hung. Eng. é Arca. 


Union, 
8 to 15, 2S &@e bending; for steel 15 
according to . in tension =) 20, 
diameter of lon- for steel in compres- 
gitudinali rods Sion 7, 10, 
and Gist. bet, Db. GCen&srai or excen- 
+? ae Reinf’t. tric compression *! 10 
28 peG.of cude 42, @. Compression in rib- 465 
resistance ai- or 1/4 tne .vea slabds=' 40. At Least 300 kil 
ter 90 days. resistanceb. compression in bdDe- Cement tor 1 m 
60 pee. sL0F Sp~ tom) ams Of pect. Section finisnea cement 
rally reinforced.crushing.anad dDoam ribs near 
bas suppopy = 70 
maxlmum’ over 
(40 + 0.05(1200 -d,) 
--- --- ae Bending. -- --- 
db, Excentric compres-= 
sion =; 10 at edge. 
1/10 allowable 4.2 4.0 , 5.0 
compressile 
Stress. 
1/10 allowable 7.0 --- 6.0 
compressile . 
stress. 
28 peG. Cube SO, OR as CE dle compress- 36, neglecting 
5 oe ne BARREL eee Bxcent ic comp- "a8 cart baie fe" apne 
ral Peiaforcemen st pression (in tae © siaerea, 45 wita 
Istance.gravity axis) 35 axial compression, 
excentric pad aeheg Ei if all acting 
ion (at edge) =! 45.infiuences are con- 
sidered. — 
1/2 elastic limit 1200 1200 
(1 /i0sef this \ 1050, or ! oh 
stress, for 1/2 elast- 
saocks}. ic limit 
For members sub- Least. Least resistance to 
jet to alternat- crusning Sin ae ey =: 140 gt 
ing stresses ana resista- cm“{ after 6 weeks). 


saocks, tne al= nee requ#re 

lowable streses rea “5 

reduetea by 25 kil /cem 

per Gent. (after 28 
days 


Note 83.p.225. 0, = maximum sate stress in steel with exact con= 
Sideratein of effects of temperature anagsorinkage, ana are ali- 
owed O, =: 70 kil /om#and O, >, 1500 kil /om™. : 

Tae 12mit stress of 70 kfl /om can onl be employed when tae 
stress in steel is reducea to 600 kil/em*, if the effects of 
temperature and Pehle oti cee neglectea. f 

Note 4.p.285. The allowable compressjseo Stresses in supports 
are only valia, if the free lengia & 15 times least dimension 
of cross section. 


4 


pee 


oh 


ms 


ale 


Papa 1 


30 


CO 


D368. APPHNDIX. 
Loaas on Intermediate Floors. 
No. Kina of Loading. ! 4 aynbi'$nr 
1. Live load for nouses, “and snali pusiness buildings wita 
furniture, persons, etc., asiae from the special load in 
certain rooms Oy aocuments, pooks, Y~oods, macnines, etc. 250 
2. Live Load 1n commercial buildings of greater extent, ass- 


emply nalis, 2 school rooms, gymnasiums, ) 500 
3. Live load in factories, when greater loads are not to oe 

assumed | 8 B00 
4, Live load for floors uader driveways and drive courts, 

if greater loaas (wneel loads) are not considered 800 
5. Live load on stairs cs: | 500 
o. Live load in attic roows of houses Hon! : pes 125° 


In storsrooms the load is to be obtained according to tne 
weight of the stored materials in each separate Case. There 
the live load for ine passages serving only ousiness pur 
poses, but not intended for use by the pupile, are tO be 
taken at 150 kil/a?, 

For document Gases and cases in registries, likewise, 
archives, StG., including vacant spaces, a Live loaa of 
500 kil/m? is to pe taken. 

Note 1. Pe. B63. Munioh reaurires anly 150 kiL\ 0? war awed vines; 
Olaenbure and the Saxon cites require 200 WAV. ‘ 

Note 2.92303. For vbal\ roons suffice 400 to 450 wAV\ m2, Yor. 
schoo ~Loors 2350 to 350 KAV\n2 (Dresden 230, Frankfort. -o-K, ; 
Ranover, Brunswick and Lioeck 400 KiV\w. BY careful experiu- 
ents about 175 KiV\azis founda suf ficrient for echool f\oors. 

Weignt of Brick Walls including 3 cm of Plastering. 
12 cm = 1/2 prick thick = 250 kAb/m?. 


25 cm = 1 ovrick. thick = 450° kil/m*. 

383 cow = 1 2 ,, .s GOO. hs 

51 cm = 2 >» 29 = 850 9 

é4 om = 21/38 ou, tend 
77 cu = 38 oo Sp = Lee He 

90 Gwae. Sas -22e0 so 1S 14B0 A) 

103 cm= 4 a ey eS GRD Aes 


Brick panel 1/2 prick thick, built of pumice, plastered on 
both siaes,130 kil/m? 

Brick panel i orick thick, similar, 280 kil/m?. 

Half timper wall, 200 kil/m?. . 


Pas 
~A, 


Half steel wall, 


A> 364 


310 


200 kil/m?. 


bending Moments of continuous Beams Lying freely on 3 and 
4 supports of equal neignt and equidistant. 


—_ 


Span 1n metres. 
distance of a section from left end support in metres. 
dead load in kil/m lineal. | 
= live load in kil/m lineal. 
tabular value. 


Cala. aero y 


The vertical axis of 
arscas Lies in the middle of tne group of beams. 
way 7 Neus eek. 


' Influeace 


Loading uniforwly | 


symmetry of the nom 


- S pancis, 4 supports. 


a 


9.0 
+0. .036 
+0 .060 
+0 .075 
+0 .0&0 
40) .O75 
+0 .060 
40.035 


+0 ..00414 
0.0 
-0 02125 
~0 .04509 
-0.07125 
-O.1 


min n 
Fe - X .% panels,3S supports. 
rn Iniluenss 
of g Influuence of p. of g. 
a + —/ 
Pan.L 0.0 0.0 0.0 0.0 
O.1 +0 .0325 0.038375 0.00625 
0.2: 2-40 .0550,'0..06750 0.02250 
0.3 +0.0675 0.09625 0.01878 
0.4 +0 .0700 0.09500 0.02500 
0.5 40.0625 0.09375 0.08225 
0.6 +0 .0450 0.06250 0.038750 
OT 40 WO17S. Osetia 0.04875 
wh! OO 0.04633 0.4638 
” 9.7857 
0.7337 
0.7395 
0.3 © =0.0200 0.035000 0.05000 
0.85 -~0.0425 0.01523 0.057738 
0.9 -=-0.0675 0.00611 0.07361 
Sup't0.9yd =-0.0950 0.00153 B.09038 
Bat 10 Sears PenO a 20 0.12500 
ranIlI1.05 
ate t 
£15 
2 
1.2661 
1.2764 


Influence of p. 


9.04362 
0.04022 
0.02773 
0.02042 
0.01706 
0.01667 
0.01408 
0.00748 
9.02053 
0.030 


J 2050 


0.03948 
0.04022 
0.04893 
0.06542 
0.03381 
0.11667 
0.09035 
0.06248 
0.05878 
0.05 


0.05 


10.005 0.055 0.05 


Tei 
1.4 #0 0200070 3 0 05 
#5 10.025 0.075 0.05 
Psb io REG 
Sncarin’ Stresses on Beams continuous over 8 ana 4 sppporis 


of equal neignt and unifordly distant. Load uniform. 
-Pancl. x .¢ panels.(3 supports). . 3 panels (4 Supports) .. 
1 influence Influence of p Influence Influence ofp 


of 2p + - of p + ~- 
d 6 EY a@ 6 ¥ 
I°0.0 40.375 + 0.4875 —.0625 40/4. + O/a500 2 0 .o6DD 
QO. .+ 0.276 + 0.3487 —.0687 440.3 4 0.8560 -0 .o668 
0.2 + 0.176 + 0.2624 ~.0874:+ 0.2 + 0.8752 £ 0.0752 
0.8 4 0.075 4 0.1982 — isa Ger pap pbes = io 1Bes 
0.8754 0.00" + 0.44012 1401 
0.4 = 0.0264 0.1859 ~. 1609" 6.0: 490. d4g6 Bi dice 
0.5 — 0.125 + 0.0898 -.2148 -~0.1 + 0.1042 — 0.2042 
0.6. = 0.225 +'0.0544'~a2794 --0 2+ 0.0604 = 6 3404 
O.7 = Ge885 + 0.0287 -.3687- 0.38 + 0.0443 - 0.3443 
0.75 — 0.376 +:0.0193 =.3043 
0.8 = 0.485. + 010149 = 4380 21004 V4 0 GO geo 4b a gao 
0.85 - 0.475 + 0.0064 -.4814 
0.9 - 0.525 + 0.0027 -.5277- 0.5 + 0.0193 , 0.5191 
0.95 - 0.575 + 0.0007 -.5957 ~ Ovéie? 
1.0." = '05625°550.0  —16250'= 0.6. + 010167 — ore1 67 
II 1.0 Shears symmetrical about +0.5 + 0.5883 - 0.0833 
1.1 tne miadle axis. (See + 0.4 + 0.4370 - 0.0870 
122°Fib. 279;) pe 290)" + 9.3 + 0.3991 — 0.0991 
1.3 Wax.V- = (a g + 8 p)l # 0.2) 4/0; 3210\— 01240 
1.4 Min.v = (a g + y p)l + 0.1 % 0.2537 - 0.1537 
1.5 0.0)4+. 0.19792-°9 


312 
D.3bG’ Table of round rods of Mild Steel. 


Diem. AX, Per. No. of rods. (Sections in cm?). 

in per cm. ri: 2 3 4 5 6 7 & 

2 0.024 00688) .0903.06.06 .0.09 0.13 6.16 O49 0.22 6.25 
30.055 0.94 0.07 O.@6£20.21 0:28 0.36 0.42 0.49 30.56 
4 0.098) 4.26 0.13'" 0.255 0.38 07600 0.63 0.76 0.864400 
5 Ostby 1.57 0220 Oseg0 50. Os78-< O.9e (4018 aay “eee 
6 0.282% 1.89° 0.28 MO.b70.96 Wiis Tat 1.90" 468 igi 
7 O¢d0e 28,20 ) Oc NOl77 MIG 16407196" 3481" 9707 d-08 
8 02505 "2381" OL800' 1.0101 bi 321016 9s" 800s bee aeoe 
90.499 2.88 0164 1.27 1.91 ° 2:54) gyi8 ayg2" 4.45. 509 
10 0.617 8.14 0.79 1.577 2.56 3.143.938 4,71 5.50. 6.26 
11 06746 3246 © 0095" 12907-2.85- (9 .BO< 4.760 Be70 6.65. +760 
12 0,888 3.77 (1.43 2.26, 3.89). 4.6275 .65' 16.78 . 7.01 “904 
13 2.042 4.08. 1.38. 2.66 «8.992 5.81" '6.6419°7.96 9.20 10/42 
141.208 4.40 1.51 3.08 4.62 6.16 7.70 9.24 10.78 igae2 
15 1.587 “4:70 (4e7). 3.64, Bi3l 7.08° Bob 40.6012 ay aaa 
16 1.578 6.08 °2.0k 4.02 6.08 8.04 10.05 12.06 14.07 16.08 
17 1.782 5.84 2227 4.54 6.81 $.08.11.35 13368215.19 18.16 
18 1.998" 565 2.64 8.98" 9.68 40.19 142,72 15.29 27,71 26,46 
19 2.226 5.97 2.84 6.68 98,52 11.34 14.18 17.01 19.85 22,63 
20 2.466 6.23 3.14 6.28 9.42 18.57 15.70 18.84 21.98 26.12 
21 2.719 6.60 3.46 6.92 10.38 13.84 17.30 20.76 24.22 27.68 
oe 6.964 6.91 5.60 7.80 11.40 15.20 19.00 22.80 26.68 30.40 
23 8.261 7.23 4.15 68.30 12.45 16.62 20.77 24.93 29.08 33.20. 
i 5.061 7.54 4.52 9.04 18.56 18.08 22.60 27.12 31.64 36.16 
2d 3.855 7.35 4.91 9.32 14.78 19.64 24.55 29.46 384.37 39.28 | 
26 4.168 8.17 5.31 10.62 15.98 21.24 26.55 31.86 37.17 42.43 
7 4.495 6.48 5.738 11.46 17.19 22.92 28.66 34.88 40.11 45.84 
23 4.834 8.80 6.16 12.32 18.48 24.63 30.80 36.96 43.12 49.28 
2o 6.486 9.11 6.61 18.22 19.83 26.44 38.05 39.66 46.27 52.86 
30 6.649 9.42 7.07 14.14 21.21 28.28 35.36 42.42 49.49 56.56 
32 6.815 10.05 8.04 16.08 24.12 32.16 40.20 49.24 56.28 64.382 
54 7.127 10.68 9.08 18.16 27.24 36.82 45.40 54.48 68.56 72.64 
58 7.990 11.81 10.18 20.386 30.54 40.72 50.90 61.08 71.26 61.44 
33 6.903 11.94 11.84 22.68 34.02 45.36 56.70 68.04 79.38 90.72 
10 9.865 12.57 25.14 37.71 50.28 62.55 75.42 87.99100.56113.13 


TABLE ‘OF CONTENTS — -'- ~ 7222 


Prerlace to tenth ealition- 


Unhanees ln this eadltion - -------- 
Nature of the Fevision- -------+--+-- 


- 


ADcrevlations Lor regulations, perioaicals 


Section i. nature ana Characteristics 


oistory olf Cement ana Concrete linoustries 

i. saleby irom fire - -------- 
Results of experiments and actual fires - 
#itects of great Heat ana water -~ --- - 

_Ze salety Irom rust of steel - - - - - 
ults OL €xallnatlions - -----+--+--- 
3. nesistance to smoke ana gases - - = 
4. Haplalty Of Construction -.- = <.- 
5. sconomy ana s 


tréngtn ---- --- 
Streneta increaséa cy age - - ----- - 


e 


neSlstance to wear - - -- - -- ee ee 
6. nESiStance to vibrations- - - - - -) 


nesistance to eartnquakes + — =—- = - = - 
Hesistance of pridge- ---------- 
7s Chéapness \eano Gurabili bys —) sige ao 
SG. Sanitary qualitieés- - - ----- = 
Y. APLLStIG tréatment- - - ---=- - 
Object1lonS to .reiniorecad Concrete, + '-4="— 
Difficult’ to Hake alterations’ — —\a - =o 


bifficuit to remove structures-— - 
Very heavy .1in CORStPUCtLGa (=) Sm ee as 
TraHsmits (Sound .Peagl ly os) pe eee 
DIfTicult to calculate structure-—i- = — > - 

S6CbLon 2s MAaLerT alsa) — (Sele 


A. Cement: -2- 9 ~ —9= tee =) = ae eae 


i. Wanuitacture ana packing Ca ata et 
WeG and ary processes= — - 8 = =.= me 
Burning cement -- ----- - = - ta 
SbOPasce (HSS = i ee are: i ae — 
Paéking 1m casks endpsacks—-—— ~aeo-— Sr 
AQuiterations --------+--f---- 

2. Gnaracteristics of Fortiana cement— 
Setting aha naraecnine periods -— SS sist 
Guick and slowwsétting cenents—- -—- - = = 
léaslog test nob ussa now in Gerwany- — — 


~ 


NERO A. NORE Re BO 
baad Or Os Or ON UY en 


> 
38, 


ZO 


Changes in volume - - -=-- 


wOVelent alter setting- 
parinkage Cracks - - - - = = 

5. testing rortlana cement 
UBUSsSAing resistance of a cube 

4. steel Foriiana cement - 
Composition - ------+--+- 
negquirements 1n constructicn- 


5. Siag Cements -- - - - - 


Bb. Mabterliais aadea ior concr 


pana, sravei, crusnea stone - 
inSpection of aggerecate - - - 
sand ano water= - ----- - 


WaSHlHe Ssana--- - ------ 


Vater preiterrea ------ 
Sort concrete - ------- 
Aperescate of stone ana gravel 
cCravei ana gravel sana- - - - 
Pumice gravel - - ------ 
Slae ana Cclnaers- ------ 
5126: OL STAINS =e sere ee 
Washing machines=- - ----=- 
C. steel reintorcement- 
Cleaning steel roas - - - - - 
Splicing roas ----+---- 
Cutting ano Oenadlng roas- - - 
nouna roas prefteracle - - - - 
Special snapes of bars- - - - 
mxpanaea wetal sheets - - - - 
ection 34 Making ana 


— 


usilag 


4. Hand and machine mixing— 
weasuring materials Dy unlt weignts 


MIXLHE Cy NRana- -— - ho 
WixioEs Cy macaine - 


ae Lntermltteat Hachines 
OC. Continuous machines - - - 
Choice of a mixing macnine- - 
Bb. MLXINE proportions - 
neaqulirewent OL compactness- - 
uSing proporbions - - 


concrete- 


ns 


cs 
SI NT ON OI 


Ni Nite NS NNT RO) ROT AT ae en 


Oo © 
NO. be Gi Orr OO ON MON ys a 


ext “Ge 
O © © 


PN NO SO ST SS 
tw) BP FE 


Da 


REGEN 


oO» 
Wo 


64 


eeblp as. steer 


& 


ca 
3 


Materlais requirea per sack orf cubic metre- 


345 


aSstimatine guantity of mwateriais—- —- 


Moae of GalcuLation - - ------ 


jaole for quantitles- - ----+-- 


i€lgnts ol waterials per cubic metre 


C. Rorms ana centering- 


nepeated use OLworms <A) Kor - aS 


DangerAtrom: Line=h=' r= i 


StPSneta OL) TOPMS He SH 


Sneataing ‘on centering- - 


Coverings for centering —- 


Supports of centering — - 


rlanea forms- ------ 


COabLNeS (TOM POPhse a's 75 


peas made separately - - 


1. 
Ze 


De 


Cerbhan preparations —- 


ae 


Centerings for .slaps- = 
Genterings tor arcies 


forms for 
rorms ior 
Forus Ior 


De. mMaKkINE 


Siab coverings— -—.- 


ACiGs 


perwmenting Iilu1as 


jar ana 
Sewage- - 
Mineras 
not waver 
Water 


bog water 


sea water 


Smoke gases - - - - 


wetals- - 


Lignting- ----- 


AO VGRLES =r =i 

peams ana i-peams - - --- - 

supports- -- + -- 7-4-7 

REL Bese a hee a ole 

concrete watertignt - - - - - 

AGaing materials to concrete- - - -— -— = 
Plastering tor waterprooring= -~----- 
Coatings Tor waterprodlineres: +e) = Con 
i | TM obeimieal Gm a Oram 

we. Protection from ¢chelimac ei1reects- -—.- 
olls-—- -— = -)- = S- =e -ae 

waters- -------ccc ae 

ana steali- - --- -- oe 

with *Garbenlc acid~wen—. Sri ie 


tlectrolysis- - - - 


—_—_— 
-_-_ —_- Sell Th 
_ =_- 
_-_ —- Sel OO lc 
_— —-— 
_-_ —_=- —_— = 

_—-——_— —_— 
_-_— ell er OO 


-_- —- —S— Oo—_ 
-  =|- eel hl 
_-_ -—- —_— 
_-_ = ES O_o 
_-_ =- Se Oo _l 
_-_— 

-_- -_ -—|- —_ = 
_-_- well OOO rol 


-_- _=_— — _— 
-_- -= —- —_—_— — 
_—_—_— _—- 
_-_— 
-— —_— —_— 
pa aR 
_-_ —- Se = 
_-—_— er Or hl — 
- =-—- —- —- — 
ee 
- - =- = 
-_-_ - -  — l — 
-_-_ —- -|- —-— — 
-_-_ - |= —_-— = 
-_- -— —-— - = 
_-_ =- —- hl 
-_-_ - - hl 


| 
KO NGRXSS 


NS We SF ers 


! 
KC 
(¢8) 


HXCELLMEeNtS with electric Curreats 


fh. ‘Treatment of vis1o 
Pacing, WasMing or orusuing 
Cement plastering - - - 
Fiasterea ceilings- - - - - 
American treatment- - = - 9 - 
Pacing \COnCTSLG, sic a 
Flacing concrete ITacing - - 
Polisasa concrete facing- 
G. Testing concrete c 

ie test: = -- =.= = 
Tests ic 
cefore blas- - - 


Tests maae 


Large or small caues- - - = 
Average results to ce taken 
Concrete Wass strancsr than 
heport of cube tests- - -— — 

Ze ‘Pests of (beatis=) <> 


Macnines Tor testing beams—- 


310 


ié 


SUrlLaces= C= x 


ad 


ana 


Section 4. Construction 


A. Arrangement of Cuilaing site- - 


in a testing laboratory- = 


céans 


- _-— - lhl 


Or pbuilaing - 


B. Placing reinforcement - - - > 


Diagrams of reinforcement, -') =) = sr 


GC. Placing ana taliping concrete 


Mixing machines set in cellar - - 


Cable raliway for transportation-— 


Hoist ana gravity aistricution—- —— 


Jamping tas concrete 
Tampine tOOLSY sk iene em 


Compressea alr tampers- - - - 7 


Junction with haraenea concrete 


OD. Precautions against colo ana neat 
Concreting 1n freezing weatacr- =.- = 


Adadusion iol Salt svete. >: sa 


frequent sprinkling in summer 


ie 


Sequence oi removal of Lorms- - — 


kh. Superintenaence ana accepiahce— 
Testing ot completea structure 


Prussian rules ior testlixr- 


Removal OF CéEntering ana TOormus- 


1 
' 


-_ =_— 


Usual loading tests - ---- - emp ee See ee St 3187 
necoraing tests - - - - - - soe eee eee mi} am ek A 
Deflection instruments- -------------+---- 136 
BROAKLER COR CS pn iS res een ee sor ras es ae aS - -139 
Deflection formulas - - --------= sh i SU SE 
Actual aetlections less than computed - - - -----=-- 140 
Deflection or elastic curve - - -'- = (—- eer ee eee 141 
Section 5. Accidents ana rebuilaing - Pp Ae oe gy, 
A. Causes of fall of builldings- - ----- age -14z 
id. Statical aefects- - Ue fy MEU ie: SP -142 
2. StPuctural Gelechee——)— aim Me eee ec ee ~142 
3. Haatls in Gonstruction=(04 ee + eine a 142 
4; peneral aetects) 2 i—. ~ iw ai as - Ge at aril Sr ae 
Disadvantages of competions in d1as We he ah ae) ~ -i44 
5. Infiuence of acclaents- ek eh ge tee rel ~\- Bae i -145 
ATOLEPALLORS + rs ie ye a ee es ar eae # - ~ 3145 
Ba 'Perwmatren’ Of  Crackse: ei ii re ere ie ae -145 
Snear cracks chnierly dangerous- - - - - ee -140 
C. Rebullaing - - ------------ = - = +146 
Metnoas suggested mB eit ah ma en ay Mi Rl aa Sarde ue SA 146 
Section 6. Basal forms, forces and moments- - -148 | 
a. Loading and span oi floor, slabs --- ------- 148°. * 
b. Members exposed to vibrations - - -- - = = .- a 
Cc. members ‘exposed to shocks = =)- = -'- wie wir -148 
Values ‘of ‘floer: loads ~ -)= >= .- i= ve ee ad Met i | ade MTNA - -149 
Weight of conerete .per cubic metre- — - - - Teta 149. 
Jing ana snow loads - - -------------- = -149 > 
Lengta of slab for calculations - - - area Aaa at ~150 
d. Slabs supporsed witn tixea loaaing- - - - - - ed 
bearing rods in a slab- - - - - --- ee See - -i51 
Distributing ‘rods in a siabi- = <9% - sieews ee ode 
arrangement of reinforcement- - ---------~ 2-7 $92. 
Moments ‘for Lbxed Slabs; aime han! =e es -~- - -153 
Slabs witn fixea ends and elastic curve - - - - = - - -154 
Console slabs ------ 7 e- et eet eet = h58 
Minimum thickness ‘ef ‘slabs~ — -j;°> \- = c< yiy lag bo SUG 8 -155 
Usual toickness of slabs- - ----------+- 77° ~156 
C. Slabs reinforced crosswise - - ----- - - -15/ 


Momeats to be employed- -.-'= -—- - = 5 tet ~45/ 
Slabs wita lengto exceeding 1.5 x widta.---- 777 -159 


Swiss regulations ---------- ------ - - 159 
Austrian reguiations- - - - - Tie euch eeslitwd octaive hie ctece: 155 
a. Continuous slabs and beams - -----.-- 160 
Frassian regulations- ------+-.--.2-2+ 2.2222 i160 
Moments te be Used we 2 ~ a er ee a ee 
Continuous T-peams- - - ---- - ja a Rae —auare Saye 161i 
Berlin regulations for slabs and beams- - - - - - - - Loi 
Wiwklen’s \¢oetticiemts, ia). a ee ete ee alle ee 104 
Loading to be assumed - - ------------ ~~ 165 
Cociticients for moments—- - - - - RAR, TE MG a ‘106 
Arrangement of reiniorcement- - - - LT ME Sa SE sul gee 166 
¢. i-beams- -----+--- -~------ -~-- 107. 
héintorcement as for slabs- -------- aL eae 67 
hecbtangular tloor wita girder Bc ee to a ee a 168 
i. Vanlts: oes ~ 32 = Rel pe ge ee 
&. supports - -----+--+--+--+-+-+--+- ews 170 
Arrangement of reinforcement for large floor- ---- 170 
Treatment of aifferent floors ---------- - - 170 
1. Lbrawings for reinforced concrete buildings - 171 
Drawings reguirea for tne structure ~ - - - -~---+- 1792 
Details ‘of strnetural members = 2-44 eee - 1972. 
Stifpaps Aad ‘nooks’ Ge. AK eae eae vee an 
Bill‘ef ‘steel requived- = S72 C205) Se eg 174 
Section 7. Strengtn, Strusses and experiments.175 
basal data ana references - ------------- i975 
a. CRusnhing resistances- - ---- - be ee - -- 175. 
hesults, of ¢xperiments- - ------- : * = ee i i76 
Factor of safety in compression - a ae, ae a aye: 177 
witect of time on Gata~ - -+-=---- ee) a ae - 178 
Prussian factor of safety ------ - ---- Bb 179 
Stresses in story columns -----+----- --- - - 180 
b. Penbile réststanceste —, soe ae ae - -— 160 
Prussian regulations ee - eR a, AO) em le ce - ~ 160 
Tensile strength of concrete neglected- ------- 181 
Tensile stress in flexure, data ----------- 182 
Go SRGATAAE FERL SLED CE = mie a ee ee ere 
héelaétion to tensile resistance- - ------- hed rite we A 
AUSEP1LAD FE SWI A CLONS bm ey ae Se en er ae tas Mager J) 
hesulis of experience - -------- (-_------ ‘483 
d. bond resistance - - - - - - ------- --- 164 
Vases | 


Derivation of formulas- - - - ---------- = -200 _ 


b. Fosition of zero line --~---------- -200 


Notation- - --- = -- eet eH ee - = = -200 
Derivation of formalas- - - - - —-- aa ~--- -201 
More convenient formula =~ Se wee ~- -20i 

c. kaximum stresses in concrete and steel- -- - -202 
Compressileée stress in concrete- pee ie a aio! ~ ~ -202 
tensile stress in steel - ~------------ -202 
Allowable stresses= (= (=) 2 o> (= ye we ae oe . -202 

a. Formulas for designing- -- - - ------ =~ -203 
Simplified tormulas for practice= = —-i> ic + > > wuneeD. 
#ifective depta to area of steel- - --------- 204 


Changing 


Causes of bond resistance ----+--5- +--+ 2052424 i84 
Limiting weasea =~) = .- -—'"s ret vs eapin) 2 sale, gps + 
French regulations- - - - - = SSS Re ae eee 165 
Bond stresses generally neglected —- - - - = ~~ —' — 436 
Deformed bata an\,bond = =) 94 — Loto Boe A ee ee 
Diversity in resuits- --------- oe deh i ee 
hesults oI experiments- - - ----- - ian) a - -i37 

e. Initial ana temperature weacarese La Ai 9) 8 -190 
Wurtemberg regulations- ------+--+--+---+----+- “491 
Cosificieéats of expansion - - ----+-+--- i - -191 

i. hesistance of steel - - - - hae ie Br i tot 
Stretcn beyond elastic limit- - - - = - ae te a ee 
Prussian regulations- - - ----- ree = dt Se 
Aavantages of steel bond in concrete- - ane -- yo aga 
dlastic limit in Brussia- - - - - - - - pa : ae -194 
Swiss; regulations -i— -05 -¢ =p = m= El A ~ = “155 

& Kiastlcity and extéension- be ina et aa ane -195 
BxXperimeats of German Comissiton- - - - sai Na it si -196 | 

‘Swiss regulations - - - - - 5 or iar a en melee, a -196 
Gonsiderc’ Ss -Fesulaai nn ea ie hee -- bite Mt -i96 
Section &. Calculation of Sing. rein- slabs -i97 | 

sxplanations- - ---------+----+---- oO Ae 

a. Cooperation of tae materialis- - - - - aire ~197 | 
Flexure of plain conrrete siab- - - - - re ee a a hy aay! 
Notation of explanations- - - - - —-- =~ ee ty 106 | 
Reinforced slabs witn increasing boaas- ----- - -199 
Hooke’s law -------------- rier eet Real ee IE 
Ffenslle stresses borne by reinforcement - --(- nie 260 | 


AS 
ey 


320 


Changing Gimensions in checking - ---------- +205 
Use of Tables on p. 209, zi0-------+--+-+-+--+--+-- 205 
Henkel*s ‘formakas)) (0-6 te a es Se a a 906 
Notes on use of Tadles- ------+---+-+--+-+-+--+--++- 206 
Table for aliferent vaules of stresses- - ------- 207 
Helation of stresses to per cent of steel - - - soe 2298 
Swiss regulations - - - - - - isa DN meh ane a fa aa 208 
full utilization of both materials- - ------ as -208 
Koenen’s formula~ -------- 7-7 = = s'= == -208 
Tnickness of protecting layer - - - - Be Le a oil Soc 
Tables for stresses and woments - - - - a Rial ai il <1 oe 
?nickness in ftuii centimetres seis ae die ae -- a ae - me aot 
WaXlmum baickness ef slaps- - - - - - - = a eee 
Proper mater ‘of gods #/—— -a)+. a Sioa eo oe aoe 
Lapor+savins books of Pablese iy ja = ee ~-- mb YEN: 
Formulas for rolled shapes in concrete- - - - --- Ai ee 
BORE LC VL iin poor un ie ree Pak ge oe -213, 
aeMaxinum utilization of both materials - - a, Tae: Mom BS oe 
b. Slab only S cm thick ----- --- rae — ~ = 214 
c. Slab to be al cm tnick - Near kh Ae a he’ a ie te -214 
Results of investigation- - - - - - --- a iets ee on eI 
DCA NP Ee eA ica i i ial Ml (Nr mncillan Sos tet ath -+ -215_ nt 
ae Théeckness of slab for -+ moment- ds Morne er eae te ~215 Diane 
0. Thickness of slab for - BOWER GS me oie - = = ~g15, 
Erample 3.5 Ws ic\ > eye et ene 
A, Depts Of aron 14 Chie x: le ml ml elie ie “eli aoel ae Sean - -21e i 
be12 rods of S: mm ab SBPROR om ali ee) ere ao te 
BRSMBL ea io hee ele ae Seen aa ee -- ~ -216. . 
Results of investigation - - ------------ -216 ios 
BXANDLESD. Hi ane a ote a Rew Wires ~ “FIG 
1. Obtaining steel section tor 60 cm beam- - - - - - -216, 
Z. Obtaining steel section for 56 cm beam- - ~ - - - ~217 
Resuits of investigation oe eae ee hee Septal ag ~ - - -217 
Section §. Deably reinforced slabs- - - wie ik Soy 
Wnen to be employed - - - mre Se ae a ---- hi 
Compressilé stresses in steel les important -— ~ - - ~ +220° 
Use of stirrups connecting roas - - - - - ------ ~220 
Comparison of single ang double reinforcement - a mya 
1. Location of zero line - ----------- ~ 7422 
Derivation of formulas- - ------- 7777 Tie ee 
Waximum compression in concrete ----------- ~éé2 


isin ae 
ge 


321 


Table of stresses and coefficients— ~ - --L4 2 2874 ~222 
Tensile stress in steel reinforcement - -----— -— -224 
Compressile stress in steel reinforcement - - - — - 3294 
Table ‘ter doubly ‘neintoerced slaps, — ae lois aioli Ue ~224 
L8ser’s formulas for reinforcements -- --~+~-—--.-. — -225 
Special formulas for the same ’-'— (62 5 29 2 2 -225 
Another method for tae same - - -------- — om — ~225 
Bxample O.- = 9s 2 - ea ee 9226 
1. Hifect of compression reinforcement- - ------ +226 
2. Steel sections reguired- - - - - Sei te aes a oe 
Simplifiea method - ---+--+--+--+- - pr ca teas) 1 ree 2224 
5. More rapid special metnod- - aay ee tom 4 ~ ~227 
Result oy Tormuias- - - - - - alliance cn - - -227 — 
fixample 7.- - ~--------- ie ale ~2247 
Caanged assumptions anda results - - i are Mies -227 
Results cis ie te So Glas ae i Peau dad as -- ening - -228 
txample 6.------+--- cays Rape) oka calles a aie -228 
Tabulated results --~--------+-+----+-- <= -— -399. 
Relative costs- --------=----+-----~. 296 
comparative economy --------- f oR eee aie ee ae 
Section LO. singly reiniorcea T-beams i! --- ~230 
Location of zero lane -~-------- Mine Wine Gaki m i 
i. Zero line within slab - - - - Scho ane g - Bag -230 
é. Zero line at pdottom of slab - - - - % - - ~ See se 
3. Zero line intessects rip- --------+-+- oo 4230, & 
Derivation of formula for last case - - - ~----- 231-5 
Distance of resultant D from zero line- - - < + - ~~ -231 
Waxlmum stresses in steel and concrete- - - - si --- “238 
Stresses im Concrete- = - -.-\- = - = = oe Aer -232 7 
Use of I-saapes Peomee = - SER MR eos ase hameiemt etre timateegye My Or, | -232 
Formulas for the last - ---------+=--+-+-- - =233_ 
hxample 9.- - - ES Rg Nae - ears -233 
CakGd lations imisg mise orien ihe cenit, oe Me ae ee bt 
Preparation of designs - - - - 5 Nahe g Soninieeea “cae --- 3234 4 
best proportions oi i-Qeans - ees tee ae Steen ee - -234 
Fortivlas and \Preshl the Sot Ry re lem i ie a 
formula for section of steel- - =.- - =.~ == + sim = =236 
formula for location of zero line - - - - ----- - -236 
table of values of coefficients - - - ----- - + ~ 23/7 
Frassian regulations for i~beams- mR itr) phos eae sar as -237 


Limiting 


‘patie 
Gis 


Limiting widta of slab- ----------- - --- ~ -238 
DW1iSS régulatioas - ttt tt er re ee ee ee + + +238 
Austrian regulations- - - ---- ----------- 238 
Wurtemberg, regulations- ~ -----------+- - — +238 
T-beaws with different slabs- ------ - + ee mie 238 
Negative moments in T-beams - ------+-----+--+- 239 
Arcaes at rlLOs- - - = - = - St ee 239 
Winkler’s Tables for negative moments - - - - - - oe We4G 
Usual breaatn of rib- -------+--4-+---- -240 
Staggered rods in rib------ ra ami ae ol il eae -24i 
Cross ribs between T-beams- - - - - Be) Sh pg geet 
Stresses in main and cress ribs - - -----+--- = -262 
fxample i0.--------- eR CN Ss sf ae 

a. Estimate of ‘maximam mouenh <= (=) 4a, =; oi ooo eae 
beHeignt h = 00 ch------ —-_--- al a Lhe a cage 
CsAeignt in is ‘lege ’- 4 =)— Vso) Oat a 
Results compared- ---------- eg A ay, ‘ = 243 
Cheekine the atresses —) 30s) see! Bk ee ete Oe ae 
Discussion of results - ------+-- 2 --- pop wt ag Yel 
Gomparison ‘Of Pesules: miei’ hie ee ge ~ ye nt --- a dd’ 
Section 11. Doubly reinforced P-beams ae Aes ~246 

Bp Lame BR OMB mii op eel oy Comet ae ee fie oe Se ea i + 4 2kb | 
a. Zero line’in slab or at bottom - - - = ra SAGE ow Sa ay 
b. Zero line intersects rib- -----+------ ce bent saat 
Formulas for zero line and stresses - - - pe aS ~ =246 
a. Accurate caiculations - - - - = enh “ Tie = hl ae ~247 
b. Approximate caiculations- - - - - < - mis. ae - og -247 
BROMD LE: 1 oy ye re erie a - - ~245 

as Accurate calculations: +) ile =) mee Pa -- - -248 
ob. Approximate catculations- - -------- -- ~-248 
Checking results - ------- icy dat es aceite - - --248 
th Section 12. Sheaw and eosa stresses- - - ~ - - 249 
A.) BhGaring SLPESSES = ei ee ae -249 

Kinas of shear- ------+-- - - ae: Na -249 
1. Vertical shegar- (== - = Selene = 2 R- - ee 249 
Ze Horizontal shear- -----+-+---- Wot o at elt ae 4 
Variations (Of. aaeanss (eos “oe ele te ie age hak oe ee he 
Formulas for shear= <= --- - —a ee er ee ee et HZ 
B. bond stresses- - --------- ailing am eee 
formula tor bond stress - - - --------77777 7292 
#ifect of stirrups and nooks- - --------77- -- +492 


ee ae 


Use of formulas ----- Se ts ee oe ee R= 253. 
M6rscn’s formula~- ----+--+---+-------+-- 253 
Shear ana bona not needed for simple slabs- ----- 254 
Shear ana bona require for T-beams - ------+--+- 254 
C. Bends, stirraps’ and books-/- = 4 - = 4 4 255 
i. bends in roas - ------+- Se ag Sapte Nay 255 
Locating oenas 1m rods- - ------ wile ar : ~ - - 255 
MWWiber of bent rods ie RT EE a a ---- a 250 
benas unaer concentratea bosdse) eee ae 257 
Ao QELPERR Sy ee eee” oo ee ee ied eh as Se eG 
AGVEaNGARES= i = = pe lied ders a 2 te in - -— - 257 
Not usually talculated-.- - > -.- - = => ik RD ~2257 
formulas for stirrups - ----------+-- a wee age 
Diagram for Locating- Pa ea ae Ae ie ah rs Ci ee 
Bxperbments of German Pommission- - - - ~~ - - - = = 259 
Table for stirrups- - ----------------29 
3. Bad nooks - - - ---.-----= Reto - - - 200 
Description - -------------------- 260 
Advantages- - - ----- 7-5 ae ee Sm 260 
ixperiments of German Gommission- ---- hana a ~ 26% 
Austrian regulations- bestia Mreita Aiello ee eat ae > 261 
Swiss regulations- - -- - - - - ~-------- ee 
fxample 12. ------------- ba i ancl 261 
Calculation of stresses ~ - -~ -------- a -- £126; 
ixample 13. -------------+----- 262 
Calculation of dlmensions - - - - : paamackn bak kaa ae: - - 202 
ixample 14, --------=-+--+----+--- 262 
1. Stirrups- - ----- te oe eee ee = 268 
z. Bends - ----- ro I Rc Oe er aa ce -- 203 
3. Stirrups and end hooks separately - - - - - - - - 263 
Bxample 15. ------------------ 263 
Calculation of stresses and dimemsions- - - - - - - - 204 
Section 13. Tensile stresses in concrete- - - 205 
®xplanations- ---+-----+-+7-7--- > --- 265 
MOérsch on Prussian regulations= - ~ - ~ - -- = -. = ~ 269 
Cracks in T-beams - - - - ------------ = = 2605 
Fropriety of this consideration - - - = = - - - = - — 265 
Prussian regulations- -—S exe FR wnt eee > 46 


a. Simpke reint’t, ¥X >d-=---------- - - - CGT 
o. Dowole reinf't, x<ae2e~27220ee--+---+--- == 267 


S- Single :reinf't, «x > @ == <5 - - eo  S  aee 


BXORPLEtEGs. we met er en oe Da irae tel rt 
Calculations- =------ rae it belt te ln ie Mh die Pass =: 
Calculation of shears and bonas - - - -~------+-- 209 

ixample 17. --------- hPa a a sake 269 
Calculations- - ----- ---+-+--+--+-+-- -~--- - -269 


Section 14. Reinforced brick floors - - - - - -Z70 
a. Kibbea concrete floors- ----+-----+-+--- - -270 


Berlin regulatiens for’ ribbed floors- ~~ -.- . "2. - 270 
be Reibforeed brick floors) +: — ~ 4 <5) — 4) oer. -274 
Prussian regulations- - ---+--+--- Oat eae. ee ~244 oe) 
tiodulus of elasticity of brickwork- r IMG Tae EGS. aS 274 
Concrete top layer- rier em cpcaatar ae raaek ts Ge ot alle 274 
Discussion of regulations - ---+-+-----+- --- -275 
fable for beams andi—beams, n = 2) ------+---+- ~276 


BXAMP LO AB: seem ok es ie om ie ts ee ee ee ieee ae 
Calculations ----------- ae ----- a ae 
Checking- -- ---------------+--+----277 
Shear and bond stresses - => ------~+-----~- -277 

Section 15.Calculation of axial supports- - - -275 
a. Investigation for compression - ------ --- “278 


Witnaout reinforcement - rain yeh hit 


iitn steel reintorcement— 


Seek oe om ae gee 
formulas for stresses - - ------------- - -279 
Percentage of reinforcement lial ae en a: NY A SES ie -250 
Too much reinforcement- ~-----+----+--+----- 286 
AUS PPAR FCZULatAGRS fmm: me ale ee a ae -280 
reinforcement by angles ---- += ---+=-=--+- <= ~281 
Columns extending througna several stories ee. eee eas 
ixample 19. ------------------ -2i 
Results of calculations for example - - ------- ~261 
db. Investigation of buckling We Tha ae eh) ha Nang e “ - -262 
Prussian régulations=.-.=) -) = ogi = in ee le a 
Paud Pht eB Pa) © Se reer he ae eee ar a ae rat ere 
Austrian regulations- - ----=-----=-+--+-- +262 
Kuler’s formala fer bitkitag= -—\sir sie ie) ~ “eee eee 
Hactor of saiety- - ------+--+--- raha ee rate i, Se -253 © 
sesults of experments @-- - - ---------- = - -283— 
Swiss regulations - - ------------+-- - -283 
Wurtemberg regulations- -------=---+-+---- ~253 
tat et ae a ~----- - - -284 


Swiss. reculations - - - = 


ee eel 


M8rsca’s rules for columns- = --—- <=. < 
Buckling of steel reds- - - - - ~ = e 


Prussian regulations for rods 
Defects of formala-.—- ~ - - = = 


ixperiments of @ertian Qommission- - - - 


Ce 


Formulas for designing- ------- 
Derivation of simplified formulas 
weonomy of concrete or steel 


Bxperiments of Austrian Gommission- - - 


iyample ZO. poncrete pier - - - - - 
MaXlmum stresses in waterials - - - -— 
Safe against bending f- ---+--+---- 


Koags saié against buckling? - - - - 


ixanmple 21. Kxample of designing- - - 


Side 25 ch -----+- ------- 
Side 20 cm ~-----+2-----. 
Side 30 em +-----+-----4 
Design by formula ($%)- - - - - - - - 


Comparison of results = - -< = = — myem- 


Section 16. Hxcentric supports- 


BHxplanations- ----—--- -+ Ne ts ly ert tA 


Radius -of kern- as, -- 
Application of load 
a Load acts within kern 


b. Load acts outside kern~- - - - - - - 


Distance to zero line 3 
ost economical design- --------- 


poncrete witnout reinforcement- - - - - 


Literature on excentrically loadaea columas- | 
Example 22..------+-2>2-- 5 
Tnree modes of excentric loading- - - - - - 
Example 23. °= 4 <r = oe me ee 
CabGulat hows pe AV Se ie i oe ele - - 
Section 17. Spirally banded concrete- - - = _ 
Explanations ---+-<-+=-+-- ------ | 

Prussian regulations . 
Formulas ‘fer Considere system ~~ - + == ei> Ries 


Abrahamoif-Magid system -------- - 
1. Production of sali section - ee a a 


Ze 


Use of less steel - -- - - + ---- 


éificiency 


gel aed geek! | ply”) | tom, Sree tat 


+ \ t 


® de - é 2 


5 aes Fed 


Oats 


326 
Biticiency of spirals -----+-+-+-+-+-+-+-+--+--- 


Hconomy of spiral reinforcement - - --------- 
W8rsca’s fortula- ------- A ai Sear agar aces gh 
Augean regplaciaw es im ie ne Steel es re Sat Bee gs 
Wurtemberg regulations- -----+-+-+-+-+--- ee 
Swiss regulations - ----------+--+-e-?- at 
Advantages oi Abranamoffi-Magid system - ------- 


Prussian regulations- -~----------- ete 
ixample of calculations - -------------- 
Bxample 24. Golumn - ------------- 
Galenbations ofl s SW eer ee ee ee 
®xample 25. Abranamoif-agid - - EP PSS SC et 
Oaleulatlons ----------+---- BP aga OS Os 
Bxample 20. Beam ------- 5-5-5 5 e- r 


Calculations: <r si ie oe --+----- ees eae Mos te 
Reiniorcemént of cast iron column - - - = - ~---- 
gmperger system ------------- UE aaa 
Table of regulations in difierent countries - - - - = 
BPP BNL e's) mil ee Me ee eer ee tet 

Moments of continuous beams- -------- 7-7 


Shears on ‘CORSE BUORS {Heams (ii Set ee eee 
Round rods of mild steel :- --- ~* << - = 5 
Table of contents -'< = — 20s Ree ee a ae 


; 
i ee oe a 
a Be a ae 
ot “apy , 2A 
f ’ ys 


DER 
EISENBETONBAU 


Teel Le ET 


C, KERSTEN 
Berlin 1915 


Translated by N. Clifford Ricker. 


A#INFORCHD CONCKHTS CONSTAUCTION 


A GUIDH FOR STUDY AND FRACTICH 
by C. Kersten 


Arcoltectural wngineer ana Royal Upper Instructor 
Fart il. 


Lbblicas vous to buildings and Foundations 
555 illustrations in Text 
seventh revisea ana auch tenversee edition 
#illiam Arost & Son 


Berlin 


1913 


Translatea .cy N.. Clitfora Kicker D. Arch. 
Protessor of Arcnitecture 
UNLVersity of Tilinois 
Uroanae iil. 


1916 


pa 


= eg a 


a 


ie, 


Fanl 


Pe 
Par aCt IO SHVENTH HEDITION. 

ils work Iirst appearea in the year i500 ana is now in tae 
/ tH sotirely rewrittén edition. Tne pook must Elve tne stua- 
Ent 4 survey Of the taniitola possibilities in tne use of rein- 
torcea concrete, ana arrora him opportunity to apply waoat is 
elveéo in Part I + 0. BRE CaS€S occurring in practice in struc- 
tures above ana below ground, so that tois 7 to edition really 
Has nOtMIng IN Common with the 1 st eaLtion appearing 7 years 
Slace. ine revision of the work was thorough ana was chiceily 
compelled by tne great progress made by reinforced concrete fed 
construction in toe last years. Tne number of iffustrations a 
ana groups or Tigures naw increasea from 467 t0555-6 in a eulae 
1nvenaea for school and practice model structural arawings will 
be more suitable for tne purpose than too lengtny aescriptions © 
ana explanations, ost illustrations -- in all 554 figures -- 
nave been wade anew. Many ot tnese (for example, 4, 438) 405= © 
#id, €UC.) are executed at a greater reauction witn black sec 
bL1eps, in oraer to secure 4 greater clearness, and in as many 
examples as possible -- wWitnout greatly increasing the book-=- 
to lnaicate the unlimited possibilities in treatment ot the. 
rors OI reinforced concrete. For school instruction these ha~ 
ve particular valueé, as they can properly be employed by inst- 
ructors in ereat part for the strultural problems for tne stu-- 
aents, 1n particular for making the penaing plans for tne steel 
(tor example, see Figs. 248, 511, 575 and 592), and diagrams 
ror alimensions and forms. (Section Vil). Por nearly all forus. 
of application are given examples of reinforcement. The engin- 
eer must receive aid from his specialists, who can relieve hin 
of the wore elementary matters, such as making the benaing pi-- 
anS anda toe Calculation of almensions, ana who tirst of all a 
are 1n position, to prepare irom the sketched data of the eng- 
ineer tne accurately scalea structural pians. For tne smaller. 
crobDlems of practice, tnat allow an approximate method of cal- 
culation, tne examples given for exercise in Section VI will 
sérve, which are increased [from those of tne first edition. 

Note Le Pe Vo Kersten. Reinforced Cancrete Canstructrson. Po- 
VU Me 10 thn eartrVaone. 19145. . 

ihe lasertion of mapy néw illustrations naturally nas a COli- 
clete révision of tne text as a result. Tne aaditions to tae 
text are particularly in tne Sections on buildings, especially 


in that on Roots and Hall Structures. Tre ‘nowleace 


s. . 
in that on koors ana Hall structures, Iné knowledge of suita- 
ole torms of roots in reintorged concrete 1s just as lwportant 
Tor the architect as tor tne architectural engineer. iverywoere 
Speclal emphasis is placed on the purely practical, tnus for 
Exalpie€ on the Construction of Watertight cellars, mechanical 
insulation, floors, COVErings of Concrete roots, etc. To save 
SLaCG, SxXteENSlVe use 1s made of a smaller type, that finally 
also presents the advantage, that one can already distinguish 
at one the essentials from those things not so -€Ssential, ana. 
recognize the. 

in a particularly tnorougn manner are treatea corbel and con- 
sole constructions, since just tnese are particularly cnaract- 
eristic or reintorced concrete construction. They are also weil 
Sultea lor stuaénts’ work, and at the same time in Statical r 
respects present no particular difficulties. Newly prepared a 
among others 1s aiso the - section On “Other Forms of Application 
in buildings” (ps Si ro a6), uVEryunere a onessided treatuent 
of tne waterial is avoided as much as possible; thus tne ende- 
vor 1s to place on paper tne ah ees tala of many in a surfic- 
léntly exhaustive manner. | 

Iné classification of the entire material is new; 1 now cor- 
responds more to the purposes of instruction than ‘Tormerly. ‘{ 
ue autaor fas labored in this new arrangement to take TEGO acK. 
count the different suggestions recéivea trom the circle of t% 
technical colieagues in tne profession of instruction. The ta- 
Cle of contents is given in a particularly aetailed foru, in 
oracr to dispense with an alphabetical index. ; 

AS in the earlier €al1tions, now again is also placea special 
ciphasis on an easily intelligible treathent of the waterial 
ana On the greatest accuracy oi all texas Tigures, so. that tne 
cook in 1ts néw wording must be well suitea bota tor private 
stuay ana for use in the special courses in reinforced concrete, 
now come into fashion. Naturally tae abundance of tne material 
to be treated 18 liuch too great, for the Guide to pretena to 
completeness in more than tae most remote measure. Tazrestrict 
whe volume within the prescribed limits, tne autnor must busy 
fimseif now as before witn severe limitations in tne diiferent 
-llapters, and tous for Many chapters, less ilportant and inst- 
Tuctive for tne beginner and tne non-tecunical man, entirely 
Chl bhEM or Oniy touch on thew briefly. for advanced Stuay a 
s'e wOosSt Carnestly recomméentea the danabucn der #isenbetonbau, 


os 
tne journal 5 & &, as well as the Beton-kalenaar; tne Hanabuca 


particularly presents an uncommonly great abundance of examples 


of construction ana of calculation. 

Note 1. peV. See the Tove of Gonrteanis of the Handbuch an Re 
YET 

Ine autnor regarded it as nis auty, to express special taa- 
nks to those firms, that nave aided nim in the composition or 
whe new Galtion 1h toe most amiable manner. Tneir names are ii 
menationea in toe descriptions of tne aitierent structures. The 
Tavorable judgments of tne earlier ealtions by the press, anda 
toe strong aemand for them, allow the nope to be jastifiea, t 
that also tAals Seventh eaition in its new torm may find a sin 


ilar recognition in the circles of instructors ana technicians. — 


ine puolisners, William wrast & Son werit especial eravituas 


tor tneir always ready supcort, and at the same tine one price 
of the oook 1s cut sligntly increasea, in spite ot 1ts increa- _ 


sed extent ana tne preparation of many new iliustrations. 


[t may be statea in conclusion, that also meanwhile a Hrencn © 


translation of dota volumes (Parts I’ and II) nas appearea. 1 


Note 1. Pe Vie LO Gonstruction in Berton armee, o vheoretical — 


ONG Practical Guide vy «Oo Kersten, translated vy PB. Poinsigaon. 


Tneenveure. BeLaeG Gautnrver-Villars. publishers. Porvs. 


wat 


or 
Hor aavancea stuay, attention 1s particularly callea ig bne 
Iirst line to tne “handbuch der Architektur”, 2 na adieren! 


X/l 


publisnea by Wiillam irnst & Son, Berlin, the classification 
or tne material in which is tne tolliowing. 


Vol. i. History of aevelopment and theory of reintorceda conereiz 


crete. (i9izZ). 

Vol. 2. Structural materials and tneir preparation. (191i). 

VOl. 5. Foundations ana wail gonstruction. (1510). 

Vol. 4. Hydraulic ccogstruction. (1910). Hmbankments, sluic- 
s, ligntnouses, beacons, cocks, ships’ tanks; fortitications, 
oreakwaters ana levees. 

Vol. 5. Reservoirs, pipes, canals. (1910). 

Vol. % Hallway construction, tunnel construction, City ana 
unaergrpound roads, wining construction,.(igi0). 

Vol. @ bridge construction. ; 


cS 


Vol. 6. wireproolting (1913), buliaing accidents, + resulati- 


Vol. Se Buildings. I. (i913). Floors, columns, walls ana par- 
bitlons, stairways, corbelled constructions. | 

Vole ioe buildings. II. Roofs, domes. “ | 

Vole a1. Buildings for special purposes. I. 3 Commenciat St 
ructures, nall and assembly buildings, manufactories ana ware- 
nouses, Chimneys. ae + 

Vol. 12; Buildings: for special. purposes. 11. Reed ®levat- 
ors, Silos, agricultural structures 

Vol. 1 of Supplement. Artistic treatment of ‘Peintorcesa conc- 
‘rete structures. (1911). . | | 

Mote 1. Part “AIL. 1 st .edvtion, Voi. If, parr &. 

Note Be. Parv XU so Est tedvivan, VoVeeley wary ts 

Note 3. Port X11. 1 st AedVtVON, VOU. IV, part 2. 


ie t 
raat 


Be rah 


2) 
i section 1. amployment in Building Construction. 
A. [ntermealate iioors ana ceilings. 

Both in aweilings as aiso in granaries and manutfactories the 
advantages of reintorcea concrete floors and ceilings 1 wake 
tnemselves always more valida, particularly in reinforced conc- 
rete beam ceilings. First tney atiord & periect security fre 
tire; tney surtrer no injurious Changes in form during a fire, 
receive no cracks ana can still support the loads. Tne enclos- 
ing concrete protects the steéci from rust, whereby special cov- 
erings and painting are unnecessary. ine Ereavtest possible se- 
curity against danger of burglary 1s also provided. Furtner t 
floors of relntorcea concrete possess a great resistance to v 
violent snocks, 4na thus are suited in the best way for manutf- 
actoricsse Tneir bearing capacity 1s very lmportant, as well as 
tneir stiifness against aeiiection. the small structural aepta 


produces a saving 1n external and partition masonry, and an in- 


crease of the neignt of rooms and windows, thereitore more aan- 
1ssiom of lignt.e(For example, Fig. i153). A further result of 
tne small ageptn and the favorable structural arrangement is t. 
tne cneapness of tne connected tloor and ceiling. By tne use 
of osams of wide span, tney are substantially Cheaper than pu- 
rely steel floors ana ceilings, betore all woen ayg1enic points 
oi view must be taken into account practically. Just in tnis 
respect are the combined tloors ana ceilings by far superior 
to wooden bean Cellings. Fillings, WO1Ch afe.So . rar, ‘injurious: 
ee 
to nealth, as they form breediug places tor wicroorganisus ana 


retain dampness, can be avoided. A layer of aust is impossible, 


Since detacned surfaces of beams are lacking. Watertigntness 1 


can likewise be obtained, ana inaeéd elitner by a suitable m1x- 


ture of concrete, or by a Coating of strong cement+1.5 to 2 cm 
in thickness (1 cement + i sand, 1 cement + Z sand + 0s) line ae 


paste, or 1 cement +. 5 sand + 1 lema paste). 

Kote ko weet Oukdelo bert, ta 45 th edition. 

Note Le Po 2 See Guide, Fart 1, 410 tH edVt1V9d8n. 

A turtner advantage of the combined floor ana ceiling is the 
criet time £or the construction. Tne rak materials are obpta&n- 
ca ln tne simplest manner and are quickly prepared. in any Ca; 
se the combined ¢loor ana ceiling will be employea with ereat 
savantage, where extensive structures are concernea. Biiterent 
forms of it, such as tne Visintini, Siegwart, Herbst, etc., A 


ba sae 


& 


/ ; 
nave the purpose by making the separate parts of tae fioor 1n 
factories, the ofission of tne always quite costly ana time de- 
laying centering, thereby producing a very important Ssnortening 
of the building period. = fo these 1s aaaed tae advantage of 
creater qurability ~- cost of maintenance entirely disappearing 
-- aS weli as tne fact, that treatment ana aaaptability oi tne 
combinea floor and ceiling is quite prominent, nowever diific- 
ult way oe the ground plan. (for example, fig. 146). finally, 
1t Snoulad not ve omitted, that tae floor of reinforced concrete 
proauces an excellent tlieing together of the duilding, which 
iact ln particular is of great importance, particularly an bad 
crouna, in wining countries and those subject to eartaquakes. 

NOt] 2. Pe Ze Just This advantage of ropid construction is 
primority Geterminative for the use of reinforced concrete in 
COLONLAL GOMGLAS, Where the transvortation of steel and stone 
way be quite APT Voult, while coment and stee\ roas ore readi- 
Vy moved, grovel, sand and wood for forms are easily obtained 

aLMost everywhere. a ee 

Protection Irom neat or cola is easily ottained by the arran- 
cement of noblow spaces, as well as by a govering of linoleum, 
ecypsumj,by a layer of corkstone Z cm tnick,? (or even by an in- 
vermediate layer of clnaer concrete and sana. Tne same means. 
are to be employed, if it 18 necessary to reduce tne transmis-— 
Sion of souna,# thorough réinforcea concrete Cellings. The beams’ 
and slabs must also tnen be separated from tae masonry, for ex- 
ample by layers of felt, corkstone, SUC. Felt is often satura- 
ted with paraffine, and is also favored for foundations of ma- 
Chines, thus tor strong shocks, cork being rather for neavy 
loads witn unimportant shocks. ! awe 

Note 3S. Pe Se Corkstoane consists of a Wikture of pure cork 
VN SMALL STAINS WITH O WINETAL BANndANE waterval, saturated wie 
th hot Fura tor. Lt V8 very easily node, fireproof, resists © 
heat and sound. . ; 3 Laas 

Note he De Be Further aee Kersten, Port 1, 20 th edition. 

For supporting tne floors are to be taken walls at least 3 
oricks in taickness (35 to 45 cm). Only for slabs of quite su 
ail spans ana loads is an exception allowed. pniviSion walis of 
‘lz or i5 cm thickness ana otner non-bearing partitionswalis 4 
are also then to be regaraea as loaas on the tloor beneath: then, 
lf they are arrangea over each other in several stories. vob 


fe) 

toe Contraryil the walls are reintorcea witn steel in a partic- 
ular way, tney way be neglected in calculating tne floor. (p55). 

AS & covering for the fioor may be taken, for example; -- 

&- A wooaen floor 3 cm tnick (best of oak)nailead on Strips 
3 * 5 cm of dovetail séction and embedaea in tne concrete at. 
aistances of 50 to i100 cu. Tne use of building rubbish or cin- 
aers as filling 1s not advisable, as much as pure ary sand or 
mineral wool. 

0. finoleum ~ cemented on corkstone slabs 2 cm thick, planed 
on both Slaes ana saburatea witn tar. ine cork unaer Layer may 


af 


ce increased to z or 4 cm, nailea as a tonsued ana grooved fi- 
oor, as well as laia directly on tne concrete in mortar or on 
not riula corkstone cement (1/2 cm thick). 

NOV] 1. Po Se , HOLeUM VS CoMposed of Two ayers of « strong 
jute fooric varnrshed on the underside, with oa covering Layer 
of oxydrized Vinseed ot, cork weal, Colophony and kourd gun. 
Tavekness 1.6 VO%38L75 we; 

Ce. ihinoleum on a Coating of mypsum Z to 3 cm toeck. 

de Linoleum cemented directly on tne well ariea concrete, in- 
asea witn snellac cement (not witn dextrine or starch paste). 

ti. Parquetry (2.5 cm tnick) laid in asphalt or on a flain f 
tloorins. | 

I. Hloor of timbers wita sleepers in the concrete. 

geeliles on asphalt. | 

he ASbestos in all colors. | | 

i. Layer 2 to 3 cu thick of asphait or cement witn tluate — 
coating. + also gypsum, sanitas, terralitn, schoja, xylolita, 
granite, etic. The top surface may réiiain plain or also be ia 
patterns. Mostly employed on terraces, balconies and in cellars. 

Note 1. VY. Ae See Kersten, Part 1, 10 th edvtion. . 

k. Asphalt on a Coat and guite ricn layer of cewent. © | 

#or large surfaces -- excepting W1ibN aspnalt layer -- tar 
Slon jolnts are preferably arranged. ie 

ror plastering 1s ordinarily taken white lime wortar, i lime 
+ 2 tO 5 Sand, GO which map also be added gypsum. In damp rooms, 
Stables, factories, etc., 1s to bé recommended a plastering w 
NlUN thinner wortar (i lime + i cement + 4 to 6 sana), or even 
& plastering with near Portiand cement. Tne plastering will be 
Supported by reeas or wiBe netting. For ornamental ceilings a 
covering of wood or of gypsum may oe foreseen. Yet 1t also sui- 
liceés, carticslarly ln workrooms to isave the under suriace of 


om 


oY 

€ ceiling without plastering or merely to woitewasn it. In 
i cases 1t 1s always to be consiaéred, that plastering adne- 
S better, the rougner tae suriace of tne concrete. ine pias—. 
ter 1s to be forcibly thrown on the rough surface ana smootned 
W208 a rubbind board. Plastering must commence at once after 
removal of tne centering. | 

Note 1. Pe &- Soe Part i. 

it 18 Iflnaliy to be statea, that a mere pleasing acbvearance 
may be given to tae HESS Dy MONLAEG bands. besides ons is aie 
W2yS 1n poSltion to Satisiy tne architectural reoulreméents poy 
& corresponding arrancement of the main and subordinate beams. 
(Also'see pe. 35). | 

Noat now concerns tne construction oi the floor ana ceiling, 
tnéen for ali sorts of buildings, however they way difier in a 
aetails, tne steel is always placeao in tae tensioned portion 
of toe slabd or ceéam, ana inaeed as near as possible to the lay- 
er of IT1lores wWito tne highest tensile stress. ‘ine tensile res- 
1stance or tne concrete tor ordinary cases is omitted from coa- 
slaeration. The aiversity in the practical concstruction of f 
tloors nominally has no influence on tne caiculation itseli; 
Oniy the Gead welgit to be taken in tne calculation will vary 


> 


in the cases. | 

Spans of more than 3 to 4 @ are not to be recommendea tor 
plane loadea slabs, Since in such Cases tne arrangement of tne — 
Supporting beams would be more economical. it is generally er- 
roneous in the use of reinforced concnete to exceea tne dist- | 
ances between supports usual in wooden ana sieel construction. 

The subdivision of tne floor according to its architectural 
form results in:-- | est 

ae #loors pdetween stecl beams, including reinforced brick 
tloors. 

o. Floors oétween reinforced beams. (T-beam floors). 

Or according to their mode of construction: -—- 

ae Floors requiring a centering. 

0. Floors witn supporting reinforcement ana only requiring 
partial centering. 

c. Floors whose parts ere made in factorics, and that requi- 
ré no centering. | 

Finally, oné may GisStinguish between: -- 
ae Plane ceilings. 
Oo. Vaultea ceilings. 


10 

#xact llm1lts are generaliy adneread to wito difficulty, gince 
wany forms of floors and céillnes may be placed in one or ano- 
toer group. It 1S attempted in #ig. i to collect the forms ox 
cellings and iTloors most €mpioyea at tais time in simple outl- 
1aé Sketches: -- ; 

ae Simpice solia slab, fixed at both siaes. 

Dp. Simple solia slac, free at both saaes. 

6 c. Arened solio slab made in uniform or but slightly varying 
tOHLCKHESS. 

Qe Vaultea slapd with plane upper suriace. 

¢. Ordinary T-beam witn permanently visible robs. 

I. Ordinary t-beam with suspended ceiling on wire netting. 

©. Brick and steel slab (reinforced brick floor with or withs- 
out concrete Conpression top slab; insteaa of ribs, one nere 
nas to ao With joints in cement nortar. ae 

nh. T-beams with inserted nollow tiles ana a cottom layer of © 
concrete. | | oe ie ae 

1. T-beams witn inserted nollow blocks, that are laid airect- 
ly on the centering’ on tae bottom are also visible only toe 
concrete ribs between the tiles. i-bseis 

ke T-beams with inserted nollow tiles of reétangular section 
on a plane bottom layer of concrete. ci 3 

i. T-beams with inserted sollow tiles of rouna section ap-a 
clane pottom layer of concrete. | owe 

nu. f-beams witn inserted nollow tiles, ctherwise as in i. 

nu. T-beams with inserted nollow tiles, that nave side projec- 
tions at bottom to avoid all centering of tae concrete; the c. 
conceete is not visible after tne removal of the centering frou 
tne celling. , apa Cece te 

o. T-beams with ribs remaining visible (naollow slabs); tne ~ 
moulds forming tne nollows (sneet metal) are again removeds 

pe Slab ceilings of beams made in factories ana aeliveret c 
complete, witn or without a separate compression layer. 

o. Slab ceilings as before, but witn nollow plocks lying be- 
tween them, and wita a compression layer to be appiiea ana re- 
intorced later. | Fine 

for all slabs, except for slab a, tne nollow forming bodies 
remain in the ceiling; they serve as side forms for tne Cconcr- 
ete webs, and as a centering for tae compression layer. 

4- Solid slabs between I[-beams and masonry. 


ii | 
Tné metnoa of Construction wlth relntorcea concrete slabs, 

lnventea ln the year ict/ by the neaa waster of réintorced 

coacreté, JOSEépN Monier, 1s a woael Tor nearly ali Lanovatio— 
) NS and patents of this kind, and nas rewalnea a Loundation for 

the Saiic. 

ine monier rloor may be Constructed as 4 plane or archea si- 

ao. #or the Monier slac for practical reasons no span'is to be 
taken greater than about 5 mw, since Otherwise the aead WElEHt 
oi tne tioor woula become too great. Tae taickness ot tne slap 
varies between 5 ana 15 cu, according to tne live loaa. . tae 
roas, which have to receive the tensile stresses, are vermen’ | 
béaring roas of tae siab. Tnoey always Lie in tne same direction 
as the smaller siae of the roon, and according to tne waeni wade 
or the benalHE mOWENE KM have a daameter of 7 to 15 mm, 2.00 are 
to be placed as near as possible’ to tne outer layer in tension. 
Coe always aoes well to employ rateer suall distances between ne es 
roas ana sail roa sections, tnan great distances ana darge s Na 
sections. Usual aistances are 5 to 15 cu. #o retain the bearing 
roas in their correct places furing tne tamping, ana vo obtain: 
a petber GLSUPloOwtIng Connection in the airection paralici te + 
bne DéaBs, the so-called ais uributing froas | are arrenged. nese i 
Ct the cearing rods tranrverséiy, ana nave tne ‘burpose OL) 
ruly distributing the eiiect of cone entrated loads ana s__ 
ks Over & broaa strip of the slab. fo tnese jisimteudal 
roas on account of their lesser 1mportance is also given a ‘sect i i 
tion smaller than that oF the cearing roas (5 to 5 mn), ana | ae M Se 
bney are piaced at distances of 10 to 50 Ch apart, SO. wna hey aM wer 
~- reckoned from the extreme tension layer, they colle ite lie 


csyona tae bearing rods, At the inters Sectlous botn ‘klnas ot * 
roas are alternately connected together by wiring, so that “tney 
altogetner Iork a stecl network. for smaller dimensions ana See 
joads baAé Alstributing rfroas may also bs omltieda in Soule cases.) 
for an approximately scuare plan the distributing rods may be ; 
1ncluded in tne statical effect (cross reinforcea slabs; sée 
Part I, i0 th edition). | 

Hote 1. o- Te PTarickness of siavos Less thon SB Ch Must not ve 
taken for oceorindy{voore (with Dive Voads). Sae Bart i. | 
5 it accoraing to #1¢. 2 wiia Stééi i-Oeaus are eiployed, bnen 
caré 1s to be taken for taeir vertical position 1n the masonry. 
according to fig. 5 a Llengsta of bearing oF 5U Ci (length of 4 
Crick) 1s recOmmendea, ana the use Of a cCearing stone or a wiia 


Leek 


We 


iz 
steel plate 1 to 2 cm Ghick, so that toe pressure on the lason- 
ry way not exceca the permissictle iinit. Besedes anchors are 
to bé proviae, bars 1 m long, 50 x 10 mm, more rarely cast ir- 
Of ancnor pilates. wxposed beaiis are protectea from fire cy a 
covering of properly shapea tiles or of mortar {cement ana ime 
mortar) on reeds, wire netting or wirea tilés,* or by a layer 
of monier covering 3 to 5 cm thick. (See Fig. 2 €). Likewise 
way be employed E€xpandea métal, as nown by Fig. 3. ~ 


| a 


Note 1. Pp. Se Tne wmakine of wire tes Vs in the forn of an 
BANCALEG WITS nHettINe with saquore meshes, on the Vartersectrons 
of which are fixed pieces of cloy burnt hard as ties hud aden’, 
CVALLy surted To HOLS the wortor Firmly. The wiath of wesh of 
the wore Of 1 WMH ALaMeter amounts to 20 wm. See FS. DL LSD s ats 

Kote 1.p. De BIUNGlly suffices also ao coatin’d of Not coar Son, 
on the freshly torred surfoce then oervnd Thrown coarse to pea 
S\Z® SONA, Then coated twice with WL Of Lime. Fe 

il no plane under suriace of -the floor be requirea (for exali- 
ple 1n ITactories ana storénouses), taen the monier slab may be 
iaia airectly on the steci beam (Figs. 2 a to g). Floor weignt 
1s Substantially reaucea, and the slab Gan be utilized at once 
as the Tloor. | 

Wooden beaks are to be protected from the dampness of tne C 
concrete by intermediate layers of aspnoalt board. . 

jy at tae building site tne floor slab be continuous and ia-_ 
1d On tne upper flanges of the beams, it 18 then to be Consia— 
sréaq if arranging tne reinforcement, that negative LOLERTS OC 
cur over tne points of support. (figs. Zc to g). if: One #1sh- 
es tO save centering, then slads 1h Uhe widta of the distances 
cétween peans may be mace in Tactories, ana then ce set invpia- 
ce in a hardened conaition. hey nave lapred or naivea joints 
ana are wade tight wita cement after setting. Finally, 4 sepa- 
rate layer of cekent or asphalt may be appliea, in order to oi 
lake Bae Iloor witnout joints. (Fig. Z a). | 

for tloors witnout live loads (for example for coverine 2 
stairway aéxt the rool tonastruction, Ior example in Fiz. i 
unese may oe placea on tne lower Tianges of the beams. \#1 

1 


re 


be 


ye 
ER « 
Zn, o). [nese vpottom flanges may then lie below tae Ceilin-, 
or Bhey way 2& concealea by a Ssuspenaea or wire netbins Cél.ifz. 
cut it is better, if tae under surface of the ceiling iles te- 


low the iower flange of tne beam, sO that the entire lower 1i- 


/0 


// 


15 
Ilange 1s enclosed in tne concrete céliing. The reinforcenent 
1s when tobe, bent. to correscond. (Figs, 2 n, a, p)s te prauset 
tne [-Seams the Concrete way extena Up Oh the wed (Pigs. Z n,b). 
if it be desired to utilize suca a ce1lling on tne bottom fi- 
ange Ior aading a floor above, tnen is nécessary a transter of 
the live load oy loam, cinder or pumice concrete. Sieepers are 
peaaea in the filling (Fig. 4) or placed on tae upper Tlanges. 
to obtain the waximum resistance to sound and heat, aouble 
ceilings way be employea. Ine live loaa will then be Carried 
On tne upper Tlioor, woile tne lower and less strongly cons truc- 
b6Q CElling has to support only 1ts own weagnt. One may also 
later for tne lower Slab use gypsum slacts Zz to 3 cm thick or 
a4 Kabitz ceiling, 1 tnat is necessarily Suspenaéa from tne be- 
aring slao oy wires (fig. 6). Tne spaces between the two slabs 
Lay remain Cmpty, ana are tnen particularly adapted tor Carry— 
ing pipes of all kinds. Otnerwise a SOundg-resisting lignt wat 
erial may be emplonea as a filling, like eypeun ruooish ashes, 
pumice sana, corkstone or clnaers. | a : 
Note 1. p. 10. The Raoitx ceiling as a rule consists of an 
WETLVNS BITH Meshes OF GBoourt S cm, made of Zincked steel wire 
4 to 3 we AVameter. The network Vs drawn trent and coated witn 
® W®Lxture Of Lime Wortar, Supsum and calves? noir WATE a Term 
ANd SuUTTFLSr.Lentyy Thiok cervling is formed, 3 to > OM, tnick, ae 
SO S22 Pe S66 | 
For alstances cetween beams greater than o to 4 mn, it woula 
not be aavisable to use plane slabs, since then tne acaa welg—. 
Ht woula become LOO ereat, ana taereiore too neavy ceans Last : 
oé taken, tnat Tinaily woula require too great structural aeptn. 
it LS then better to take Monier vaults D: We Ae in thick with 
a rise of 1/40 to 1/i4 span (Hilgs. 72.5). Teo small arise pro- 
auces too great horizontal thrusts. For the meaium thickness 
of tne vault tne steel network is arrangea at toe imposts, ana 
1S cComelnea ln the same manner as Tor the piane siaos, except- 
ing that the bearing rods are curved. Such an arrangement cor- 
responas to tae effect of a unitormly aistributed loaa at poth 
Slacés. Yet -— witn one-sidea loadine of tne vault or With con- 
tratea loads -- tensile stresses may also occur in tne uppe- 
cr zoné. In Sucna cases 4&4 aouole reinforcement 1s recommended; 
fle. © Snows a&@ vault-like trestment or the floor siab wita a 
iblanée top: tne reinforcement is partly bent over the flange of 


wie Dea. (Fig. S)e } 


/k 


14 

Monler vaults are naturally supported on the bottom tiange 
of the péaus. Hor a filling may again be taken Ginaers, lean 
concrete, ¢tc. Double vaults wake tne floors more secure agai- 
ost souna ana néat. One can also here,.as for tne plane double 
tloors, take for tne lower slab a weak suspended ceiling, sus- 
penaging it from tne vault by wires, 1f necessary. 

Vaultea siabs according to Pig. 2 1 present the advantage of 
a greater aegree of fixing at the enas. n 

ita Koenen’s vaulvea slab (Fig. 10) tne closely placed rods 
run in Gatenary Iormw at the m1adle portion of the slab, plane 
oenéatn. AL the Supports the relnitorcement rises Willa toe opp— 
osite Curvature tO near the top fiange oi the slab, where tney 
aré hooked on the top flange of the beam, or are extended 1nto 
bone adjacent panei. Division oars are not use. Tne rouna steel 
roas arrangea at the CalculateaG distances in bwO adjacent pan— 
cis are placed alternately as in Fig. ii, so that they pass a 
each other above the beam, and champ it trom tots sides. las 
top of the slab must lie su isase 5 Cis above tne top tlange of 
bne beam. i se ah o asee gai 

by tne mode of Tasteninge the be ering roas ana tne form of t 
tne vault, the slab is fixea at ine supports, ana the positive 
cending moment at the miaale of tne slat is reduceas Toe incr=— 
asea deptn of the section next the suveort likewise ‘corresco- 
nds to the increased shear tnere. At tne same time the vault 
lasses protect from fire and rust the deans enclosed by. then, 
so that only tne bottom flanges of taese need be leit bare. 
sesiaes the vaulted section with the beam forus an effective e. 


architectural treatment of tae great suriace oi tne ceilings 


As between beams, so tne vault slabs may be fixed directly bet 


ween tne walls by the aid of anCHOrS. In case fixing at an exe, 
teroal wail be impossible on account of insuificient loaaing, 
tne slab is placed free taere witnout Lixing, os that 18 exerts — 
only a vertical pressure on the support. The bearing noas then 
remain in the lower tension zone. 

In the pumice concrete floor oi tae machinery buiiaing oi t 
iné Augsburg-Nurembure Co (Fig. iz), gravel concrete is repla- 
cea py tne so-called pumice concrete, a mixture of Fortiana c 
Cement, pumice sana + ano some guartz sana. Tne reintorcenent 
lS arranged in tae same way as in the skoenen Tloor; yet insteaa 
of round rods are employed steel banas laia flat witn small a 
angles riveted on.(See MBller’s system. p. 44). 


eae 
cane 
ry 


Kote Le Pe da Pumice sand Vs of volcanic oan ond vs eee Bee ie mes 
ained AW the visinity of Keuw\ed-an-RBhine. | SOG e oe Maa ANE Cn 
Fumice —e flcors nave certain advantages. Tney are li- 
Hu, thus requa ing swall £osts of foundations, ana guaileriy- 
sectionse They -have great isolating properties, tous affording 


200d resistance to heat and cola. In consequence of tneir por- ‘ 
ous structure taey are particularly resistant to sound. Plast- 7 aS 
sting and stucco adnere finely pecause’of tne porosity. Likew- — Ne 


lse@ Sweating and dripping are avolaed, as snowa by experience 
ol mwany years. Ins. resistance or tae concrete LS ingeed baut.os 
small, woicn results in relatively thick slabs. ‘The very COON eo 
ensile Strength also perhaps makes: easier tne foruation or ees a 
, cracks. #inally, ‘bhe objection is. Now: entirely justified, ee: ‘*. 
pumice Concrete Can ailora but ‘sligat provection to tHe steel: ny 
on account of its great porasity (even wita cy rica mixture). 
vurtaer, see p. 102, as well as Part De oe, | iy ne 
Sometiues are seen’ floors like. RYE 13, waere wae pusice con 
srete is employed an the middle of | pane ceiling in: wane ‘bension 
zonée This results from the dea of using the eravel, concrete i 
only ab bhe Supports (on account of tne shears), and in tne e 
compression zone, but tne pumice concrete only where stresses: 
10 NOG properly occur, since the tensile Stresses are baere ot 
vaxen by tae steel alone. Sucn constructions -- already Fan Cuan 
tae reasons given above -- cannot be rigntly LORE fae a 
(iy because a wis tse) or ‘the two kinds of £ oe tone | 


LLy occur. f 


ing idkes vada: ribs, La 
Layer On tue underside of une ceiling consists of gravel cone 
reve, while the intermediate spaces have a falling of: cinder ) 
concrete, light ana stati@ally ineffective, to reauee te ges ee 
veigote Tne supporting rits are stiffienea by cross ribs, Sa Oe can By 
wnat rectangular conaer concrete panéls are producea.: ee 
for the Lolat floor (Fig. 14), tac lower reinforceuents car-_ 
ried barough between tue supports, SO. that at each point of & 
iné slap tensile stresses from positive bending moments can ee 
received by the steel. The tensile stresses in slabs continuous 
“i the polmts of support are taken by sorter bars, extending 
co 1/4 tue span in tae panel and ancnored en each side..[ne a 
cistances pebween all reinforcements is ensurea by bhe so-cal— 
Lea type stputa; arranged in’gigzag form. Algo aigese eurved 9 (0 ©) ua) 


ae 

: 
fi , 6 is 
. Py}! 


a 


by ME aa GAGS Ce ATR eR a ese vata. ae 
are used, “that especially ab ane npver VE eee points Borns! 
: to. receive the steel rods S, as Fig. 15 shows. THis there— 


re produces a at the builaing site the practical advantage of t 
s less: ‘aependeat on tne “skill or tne ‘geodwill of Ake conse oe 6 upon 


“wor kii Lene 
ewe orick esetings and tloors. + as 
Le ne ‘AL. AVso see Bart Zs ase Kersten, Stee » pap iRenicgt a ea wae 


tion here, since Wes are very fe de ‘ain’ ‘statical resrects, 
‘ordinary floors of reintorced concrete " ae 
kmown nas become the Klein floor \Fis.. 46). with ie a 

this form of: tloor One 1s Rov restricted aie) any. definite 

f tricks : he ‘way take either solid or hol LLOW, porous: or cf 
On de: in. the tension zone cand steel is set on edge oe 
sen the bricks. The mortar mixture is ‘not made: le eaner than eas 
ment +.1 line +°5. to 6 Sands For. constructing the: ‘floor is ree 
Ssseary a i age abet centering, se pei 2 fastenca te one ° beams | 


ae tebelut ate not. 
| ally at the middle of 
into the compression | a 
eculiar end nooks or anchor r plates. Hor ‘rensnitving ae 


ue Sses is made, i Eastin ¢rom the end “fasteniaes ane en 
Aa tae roas, .QUuiTE in the sate manner as “in trussed Tea tar a 
where the massive | Pas resist ae Lael at hh piresses 


aad 
sound is ce ti anent puedes fh Thee Ve iis Mea 
Fie ss skeaeleaks woes seat ee everywhere can be Pe ee Ree Se 

the antes sec a ke ae Lae | 


sn tae horizontal. 7 | dagen 
The well knoan Férster floor: hay likewise be constructed mite 
eel reinforcement, and then presents manifold. advantages. 1 ! 
3 spaces for ‘tne ‘steel Teiator rcement are obteined, when wie. Ny 
of the pnollow tile lying between, the tO" holes: is” picked 
py the hammer, so that the tile has a. hollow form. In these 
anoles are placed reds and: bands, which ere’ ‘then coveréd by ‘mone | 

dais: 18). This peer th ais i ae opreloblarty ad~ ‘ 


paeton t joint, 
Bo material ae the hollow tiles, 5 


stetical respects, one here has” ‘to ae with ‘Tbeaus, ae 
on by ribs is ery | nerrow ihe ay Cah ak ea big Mis: 


tne Reet Or? stucco 2 toni tet 


it Netuer & Jacoby ot Strasburg introduced in tae. trage” . 
ot black sheet iron with arrangements | for the accurate. Peat 
ishnent of the distances between the forms. The lengths oes. 
sheet form generally amount to! Le Om; yet forus cen be Cee ah 

ae ee to 205 rm aaa | 


18 

fixing and stificning the form may also te employed hooks or 
bolts, that fit into corresponding holes. To equalize at the 
enas are arranged guides with or without sheet facing. The sh- 
ape of these Srouhcs may be as in Fig. 21 e or f. 

Jn Fig. 22 is represented the section of an Ast floor (id. 
Ast & Ca, Vienna). the ribs are about 50 om apart. The illus- 
tration shows the addition of a plane ceiling. 

Best known is the Koenen’s plane ceiling. This is a slab.na- 
ving rids or hollow spaces, that is connected with a plane eb-: 
iling extending continuously beneath the ribs. In ‘consequence 
of the hollows the plane floor is very light, and still prote-_ 
cts from sound and heat. It is also” particularly suitable tor — ve | 
the addition of circuits of all kinds, as tao as for ventila- Ma iy at 
ting ducts to tne stoves. i a iat Hae 

Transverse and longitudinal sections in figs. 23°24; show 
that under the ribs freely supported wooden timbers. or ‘strips a 
are eater acat that may have Rscpagr st amb Beh iaieh The ‘Strips make 
as @ convenient fastening of the plane coud: ee in the 
ribs of the bearing slab are bedded steel-rods of 1 cm diamet- 

er, naturally as low as possible, fnickness of compression. slab. 
5 to 10 em. With. the small distances of 25 cm on centres of r oe ea ae 
ribs, the plane ceiling is formed in the: simplest way by nailed | : 
reeds and plastering, or fastened by zincked wires, | ‘(witnout ms 
centering), by plaster board, clay slebs, wire netting and pl 
aster, and the like, or an ornamental ceiling of stucco or kor © 
wood may be directly fastened. The plane ceiling extends cont— 
inucusly beneath the ribs, so that a fracture of, ss along. the i, 
ribs or an appearance of the latter ‘cannot occur. For: the has 
pose of tamping, the wooaen beams. support sheet ‘iron moulds s 
about 1 m long, that can again be removed atter tamping. A oh 

Greatest distance between girders is 3.5 1. “For heavy loads © eee 
tne effective heignt (h - a) is increased by extending the con- an 
crete ribs down to the ceiling beneatn. The wooden beams placed 

orrespondingly lower are resoved with the sheet metal forms 

fter tamping. The ceiling beneata is fastened Re ae concrete 

by embedded supports of zincked wires. 

3. Slabs with nollow- bilocks and plane. under surface. 

#loors of reinforced concrete with hollow blocks are especi- 

ally suitable for houses ana commercial buiidings; they possess 


pe »y 


two advantages over solid floors 


4 


‘vantages over sclia floors; first by the. kvcan healt OL fas: Oe ab aac 
2 internal hollow space, an intermediate layer of air, the COE yee os gag 


ovection of the floor from.neat, sound anc dazpness 18 cOon- 


per - improved, and secondly it is tossible to build such Reg. 
~ cleors with bat small expenditure ot materials, and still to. | oe, 
CHR COR ISE 8 hee eet aOR, ehich is often necessary for, > 


weCMic al, Dam ieery ‘Ble practacal reasoos, These tyo advan-— 
tases méy be obtained bore or Less, when to a sclid floor #1Gb 

sting pres @ Rabitaz ceiling is afterwards suspended (Figs. 
2 6). Eat when floors over | rooms with high internal tempera 
ture are concerned, and. particularly those with great. Gampness _ 
or thé eit,’ 1n, certain cases 2a rapid. swelling and ory rot eat a 
the Rabitz ceiling may occur. For. producing the. hollow spaces Hi AN eae 
partichlarly serve Light materzais like pumice and | cinger con , ee ae ok 
crete, gypsul: blocks, ‘hollaw: wiles, wire and, reed forus, 4d eRe a, ee 
cet metal and the. like. All these bodies also serve as center- | Ree eee 
Ing) #6 tne ribs. of the si ao and permanently remain in the. fl- | 
core It one. objects: to addin 1e Ey ‘visible ceiling layer: beneath | 
(tue i. ky then tke construction OE the oiling may save in 
ccaterine<lumber, as shown in Pigs. BW “3h. un ek Ca 

Xotezis pe 20s Qn cocount of. the. ‘elignt. forms node of cob | 


ind 


Lampedeconenete cannot we employed, Rut onby asst. concrete. 
That 19.%0 be constaened o @isadvantage, and it nokes. ane ‘use 
of such {loors res 9 ibs ocd ant Spans. - Sui e\\ 


-ensiop zone and lower part. (Of “tne compression boned replac 
cd by PAent, thin-walled hollow tiles of burned. cia pe A NaN ee SN. ge. A 

conerete. Ine concrete ribs. between then are reinforced By BO a! OR 
-na rods. Tae hollow. tiles way be laid directly on) tite. center- hh heat tp 
‘og, Of Lnairectly on a previously applied. layer of concrete. _ ay ae 
(vice 25). Tne hollow blocks are held to the ribs by friction. 
loliner’s cellular tloor, is also. employed in, connection with 

|= beams. 

milar is the Neakphads tieor be deinticn 1 hapiphags reo: Ber- 

ins Be rticularly notable in this. floor is. the fact, that the. 
collow spacés of the hollow tiles are closed against. the cen 
‘nt mortar by pasteboard, ends. It is in this maaner possible _ 


yk 
+ 


oS 


20 3 Ve 

to reinforce the floor crosswise. fhe formerly mipleved roller 
Staps 1 nave been disused. In the new form of floor of the West- 
poal construction, the Havag floor, the hollow spaces are clokd 
og stretcned strips of paper. With this form of floor one is no 
longer restricted to blocks with round holes, since the paper 
strips employed are adapted to all forms of noles. The Hawag 
floor presénis a network of intersecting and strongly. connsct—_ 
ead reinforced concrete ribs with the hollow tiles lying. between 
then. €f the thickness of ine tiles be statically insufficiest a 
then an extra thickness ‘of concrete is applied: on. the. blocks, gas 
Fig. 26 shows thé use of the Westphal floor for a D-beam ceiling. 

ROte te Peo 2ie This wodte of closing is eSpectary suited for. ae 
oVocks with round holes (Pié. 2). In. «Ne | construction a yposte- 


voard of rectangular shape Vs volves un and by Means Of: ‘grooves 
in the opposite hollows cf two Blocks Vs extended. throush. Ane 
Vatermeciate joint, 30 that. the ends. OTs the VOL enter. the el 
Vows of the blocks for.a fen CMe In consequence oft VWs evasti— 
CVty, the rolled paper then unrolls and. thus. ‘Vent closes. a aes 
the SPAGese — - as ’ . on 

Hollow blocks closed on all siges are: dear and. are pike made 
wita difficulty; the rolled stop mentioned always” forms a sin- 
vliftication, but has the: Siaianis, torial that) sei ar 
oss rib must be Perr cee ees? ER ee , 


sifted coke ashes, = ig and sawdust. tne ete are. ce. 
cast in moulds, in which is first placed thin tarred roofing 
paper, which then forms the external covering ‘of the blocks. 
The paper adheres well to tne block, “and an the construction 
of thé flcor prevents the: absorption of water ‘from the concrete. . 
According to loading and span different thicknesses of eg Ds 
are employed, and a compression slab of varied thickness. 28 PRE ee SS 
Tormed above the light blocks. The construction | or the floor a rete. 
is evident from Pig. 26. - Ss 2 py ae 
fo a similarly invented idea corresponds | the Sieg floor (Fig. 
<9). The hollow bodies serving as centering» as well as tor the 
an consist of a mass of eyosul, in which wire network and 
eds are so embedded, that this nas a sufficient capacity. of 


a9) 


Tne nollow blocks are not over 2 a long, and ate laid on tim- 


re 


Dee t 


43 


21 | aed 
timbers about iz x 14 cn, that must be placed under the joints. 
to protect tne nollow blocks from penetration of water Guring 
the concreting, they are saturated beforehand Retn & méans of | 
waterprooring. | 

fhe mode of construction of a hollow block floor of %&iblin 
type, (Fig. 30) is as follows:-- on an intersecting structure 
or centering beams, which at the same time forms the bottom c 
centering of the concrete ribs a, are set previously made hol- 
low concrete blocks b witn the closed side bénéath, so that oy 
open intersecting spaces connect them, in which are placed the 
reinforcing rods, and: which are later tamped | in. as concrete eS 
beams. At the same time the upper apen side of the hollow ble- ; 
cks are covered by an also previously made thin reinforced con- 
crete slab c, 2.5 to 3 cm in thickness, on which is then laid) 


an upper layer (both the slab and compression zone of the beam) 


of 5 to 7 cm thickness, with the necessary: steel reinforcement 
roperly arranged, and abplied at the same time as ithe: connect— 
ing of the beams. For a better. connection of tne covering CLu 
the nollow bi ock: with the upper layer of conc crete, tae former 
1s fitted with a projecting strrrup fi | 2) Ac 
{Tne hollow blocks have a sige of 96 cn square with 2 ras i 
stiffening ribs, thus a section according to either ox 31 or 
32. These are of .pressed cinder concrete strengthened by. wire. 
netting; the walls are 1.5 to 2 cm thick. The hollow blocks | 
are made in neights of if to 40 cn, SO. that the total depth of 


tne completed floor is 25 to 30 cm) Bad its dead ‘weight from Pa: : 


215 to 395 kil/m*. ice AS Reva an 
Wayss’ reed tubular floor, wig) 33. paculdar to this. floor | 8 
is the filling of the intervals between tne ribs’ by the ‘so-cal- 


lea reed thus ar cells, which at the sane tine torn. ‘the. center- 


ing for the Sends of the beams, for the slab, and also. the and= 
er surface. The reed tube is a hollow. Torn. ion long. made of War 
ven reeds drawn over wooden forms about 25 om apart. The reeds 
are neld to the wooden frames by steel bands, so that the reed 
tabric has the necessary strength during the construction of 
the flicor. To produce the tubes serves the reed tube emchine, 
on which a workman can wake in i0 howrs from 200 to 250 tubes. — 
Tne materials used in reed fabric are 0.5 to 0.6 cm thick, cl- 
osely wnven -- steel banas iz x O.5 to 0.3 mn, traces 20 ma 
hick, are not dear and are very easily obtained, so that the 


+ 4, 
i 


Me vialeg ate 
Behe 
mee? sie 


ee 
We? aed 
Bey 
fiasye) 
UES} 


22 
tubes may be taken to tne building site ready for use. ‘The tu- 
ces are extremely light, about 5 to 8 Kil /m- of area. For tub- 
es of greater dimensions may become necessary a middle web as 
in Fig. 34 d, so that it may tgs eB without breaking 1 the load 
of the applied concrete. | 

The construction of the ioe is exeouted : on a plane. center- 
ing, On which are laid the tubes at distances corresponding to 
tne widths of the beams. The connections at the ‘ends of the t 
tubes are made by Slignt overlapring. Wher € the floor must also 
receive the load of a partition wall is assumed a. correspondigs-— 
ly wider beam. By the use of tubes of lesser. weight is obtain- 
ed ln &@ simple way a thicker compression zone according to Pig. 

ee, &@. Hig. 346 shows the construction of 2 beam supporting a 
wall of great weignt with treatment of the projection: by fil- 
a With reed tubes will be secured an ig ltt BRU ane | in ; 
ncrete and 1n weight. 4 ee.) salaron 

if one desires to construct a f-beam floor with plane cae 
ng, the simplest method of construction is taAat: ‘iven in Fig. Mb : 
24a, where the outermost célls with their walls form Coeds 
tering of the beam, But such e floor is even scarcely dearer 4 
than a floor without plane ceilings, since ‘it only. makes neces= 
sary a plane centering without cutting ‘lumber LOD the Biba. ne 

Tne plastering is easikty applied on the. ceiling. an a compl-— i 
etely reinforced underside be desired, then ‘before. concreting eae 
are: inseriea reed strips in the webs; these. remain aiter ‘the- 
Setting oi the concrete and themselves. BSSIB bys Coe | 

In the Bacula floor (Fig. 35) instead of the. reed. tubes Le 
&t resist tamping but little, there are taken wood strips” of | 
© to 10 cm sauare section, where the Strips at intervals of ot sean 
am are connected together:ipya mat of Wire netting. ‘These mats) 
are n@iledon tne sides and tops of square | ‘Trames ‘of! square st-) 
rips. Fig. 30 shows the frame and centerine of. the ceiling; t ar 
une célls extend from one part to the next. ee 

In the box floor (Pig. 37) the boxes are open below and are 
mage @L boards 1 cm thick. 

Tne nollow reinforced concrete ree Wrissenterg seat. 4 
(figs. 36, 39), shows hollow blocks of light tubes of thin be 
ack sneet iron with overlapping ends, that are to be had every- 

re for little money, and not as the case with shaped nollow 
clocks, cteing subject. to a certain loss of pieces by injury in ae 


transportation. 


Ae 


a3 ; aay: 

The use or burned hollow tiles furthermore dobenariy Saaken’ 
interruptions in the work by delays in delivery, defective bur-— 
ning ana the effect of weather, which cannot occur in equal m 
measure 1n tae construction of the Wirissenberg floor. 

The procedure im constructing the floor is the following: -- 
on the plane centering is first scattered a layer of gravel a 
about 1 cm thick, then the separate tubes are joined together 
with inserted ends and reaching between the supports, being 
joined in pairs by simple stirrups of round -rods. The distanc- _ 
es between pairs are determinéd by statical calculations. In | 
the stirrups are tnen placed the ceiling rods (diameter & to 
13 mm); the strong bends of the stirrups in the ribs give as 
secure pedding. But 21f€ the floor extends beyond supporting Wwa- 
lis or beams, then thé steel ‘is to be bent upward according to | 
big. 39. Then the strencthenimgapipeware completed to about Ue 
the. tops of tne sheet metal tubes, and the intervals between 


vairs of tubes are filled with cinder or pumice concrete, whi-~ 2. <4) 


Ch taen Goes not come in contact with one reinforcement. After 
the tubes are thus enclosed by gravel and cinder concrete on. 
all sides, the Likewise previously calculated statical compres—_ 


Sion slab is tamped in gravel concrete cftat least.5 ‘Ch, ‘thick- Os 


ness. The tubes must naturally be stitf enough. tn offer ‘the a 


necessary resistance: to tamping. Care. me also. to ‘be ‘taken, ind 
at the reinforcedetiering rits are always connected to the ¢1- 
cor by fresh concreté, since a crack there might become. danger- 


ous in certain cases. Sut the precaution is easily taken. Roe 


prevent the entering oi the concrete into the vabes, their ends is 


nay be pressed togetner. 


ror schools ana hospitals the ‘Wrissenberg floor. is pent soi 


ted in so far that the tubes may be utiliged as ventilating ad. 


ae 
aucts, and at any lees: as tor supports, oben ney be made 


at the suriace of the floor. 
{he transition to the next group of floors is eouved by the na 
nerpst (cylindrical web) floor (Pig. 40). It belongs to that 
class of floors, which make, unnecessary the always Ovherwise | 
required, but dear and time-wasting centering, only requiring 
some supporting timbers for the middle of tne larger spans. T 
Jane bearing webs of the concrete, reinforced with. steel bands,” 


are made in tne factory of cinder concrete or commonly of bur- |) 


nea clay. The webs have a height of ZO cm and @ distance on © 


* centres of 25 cm. The cylinders are 25> cm long and are’ lert 


LRH rath 


is 


f 


24 
rough outsice to increase the cond. 
ine Lhooris without centering and witrt a few beams ts coven 
red by some mortar and is then furnished with any kind of flo- 
oring. The structural depth amounts to 22 to 26 cm including 
the plastered .ceiling, 3 
In statical respects, the entire floor forms & united support. 
The tamped upper slab increases the effective depth of the beam 
and forms the compression zone. Belore the upper layer or con- 
crete nas acquired tne corresponding strength, the floor must 
only be so far loaded, as bea Ter: by the concrete rits edo! 
taus without the aid of the slab. Oe 
4. Ready wade beams witaout EE ; Meas 
Some floor patents aim at the purpose of already pamcing ue 
supporting members on the level ground already | betore their. Bie ae 
special use, tnen alter the lapse of some. weeks ‘to ‘set then in 
their proper places. Such a method of working reduces in. great 
measure the cost of tne local construction or tne’ floor as well 
as tue building period, and permits the erection at’any season 
of the year. Likewise all injury of the masonry by. the concrete 
workers is avoided. in conseouence of bhe : Tactory ‘production | 
of ‘certain parts, results a better control ofr tne work, ‘ana. uv 
thereby the obtaining of greater strength. ‘Yet. t¢ must not be 
omitted, that only ty conscientious work can: ‘be created an ef) a, 
vective combination of tne different beans pads’ ate different as 
times. Further, the connection of the parts of the ploor with 
the other portions of the structure, “such as. walis and | sairders, 
is by far less intimate, as that to. which men are ‘otherwise ay 
accustomed. Alterations in the programme of the ‘building are 
not as simply and easily made as with the previously. decoribed 
forms of floors. There is aiso required a Ereae factory. with 
2,corresponding outlay of capital. . oh ae eee ey 
The Siegwart floor consists of separate totter bears: of rein 
reed concrete made > in factories énd founda in the trade, the. | 
ae YS Siegwart beams, 2) ch wide, teat only. need to be laid 
ceside each other on the supports, the joints being tilled with 
ine cementing material. Tne floor itsels is pre perly then bait es 
plete, can at once be loaded and be useq for terther masonry , 
work. Tne setting can be done. by anyane witaout. ‘previous expe- an 
rience, and it proceeds so rapidly, thet 4 to & nen “ig conpl= 
ete more than 100 m¢ of floor. | ge vera ie as 
The manufacture is Gone by. machines. ine SC NS 


25 | 

consists of round rods, that are. partly. bent upward ae ‘the sup~. 

ports. Tne interspaces between the set beams are cast in rein- 

rorced concrete, SO. that the sides of the beams are left rough. 

toe Siegwart floor can be employed both for freely supported 

ends and also between girders. (Figs, 44, 45), 

Dyckernoff & Widmann Go. produce in their Carlsruhe factory 

different beam sections, Nos, 12 to 23, named frou the depth 
of the beams in cm, | | 

30 =n the following Pable are wel lecwenl the acada . welgnts and al- 
towable .bending moments for Te = 1000 ‘kil om? | 


6 


section. Dead weignt. in kil jm. ~ Bending moment 1 i for dead | 
4 beams set side by side. and live loads in cu/kil } 

Now a § % AN: he | _ (for 1m wicth Of floor). 
a eS adie Se OE ae aD Ay Me 78,864 
15 ASA B GS TO Ona eae) | 06,7865 CG ROE 
he, GO RN ae aera Vane 
Za) Te 490 ANE RR TGS ioe Re Ne 
2278 OM EEO a ea et — 
23 Bot a0 ee bor 275, 451 : 


fhe calculation is: made ‘graphically with: bhe consideration oa 
of rounded vaults for the: upper i~ cea. eS : ‘ Ore an on oe 
Note Le 0-80. On ‘Ane use of. Ae ‘SVedwart soeam.. see. B & ay 12909. “ ut s 
ps 68626, 1902, pe 192, Movies Ba pout. “Cement Supplement” 42 s 
Visintini Stuer beatt tee seb ‘Yisintini: enlde otual) 
lattice girders. in reinforced concrete, 45 40, 40 cn nish and 
_O om wide, in which tne members having to rective. sobiecant. 
le stresses are of concrete alone, woile all other members, 
hat exclusively ‘or under . corresponding loads receive ‘tensile 
i stresses, are’ reinforced. These reinforcements in the chords | u A es 
consist of continuous round rods, in order to place the reint-. a aan 
orcement of the diagonals with: their curved ends. The enclosing — hoe 
concrete mass at the cennections prevents any ship between the 
eel of the chords and the Giaggnals, and theretore acts as 
2 riveting together of the Steel) reanforcenen ts. In the members 
of the compression chora stecl reinforcement is not aluays | di- . 
rectly: necessary tor strength, yebtit:is: required on @rder to 
ensure 'ta¢ Ones E Nien of the chord and: diagonal reinforcenents 


in &@ Simple way. 
At the “junction of: two Senne lengthwise; ‘there is formed a 


oe 
oer 


es 
Packets 


f 


ah 


26 Se Mi Ge Be aN 
dovetail groove and afterwarsd filled with cement mortar, it = = 
affords sufficient security against the separation of the jee # 
us, therefore against longitudinal cracks in the ceiling. ee 


add a wooden floor, small wood strips are nailed pay the dove- oe 
tail groove before ‘the cement tart icha ‘en which ‘the floor | can eS i 
be nailed. mec uee i Le Peale s oe: ae. ’ 


ib 


The manufacture of the Visintini beans is’ by, MSEDS | of nooden Abe e 
boxes with steel moulds, and need not always occur in the fac 
vory, but may be teste de “Ln the ae ane Sime ie a 


(opentnns at the or | ca Sore ‘ 
45) consists of. o ne ee 


by (sakes bere 


| 6. 30. | eter 
Kaige MBER! 2 
purpose of receive the Shears: and neeevave. eee th 
supports. If & vi 
are laid in ere ahoue each other, thus: lcoanaietail 
of the ribs. + Then the upper rods. can te bent upiart 
Coney the sections ile ddezenetay, beside, med 


ing, as welljas the o¢currmenace of cracks In. the: ‘bottom surface 
of the ribs. 3 | : ie a Ca ie, ue 
NOtS Ae YsBle 1h. tha ered rouse An 1 ‘soa! We Bg severay a 


V Wiad 


ers over each other, Yaen eooh Vouer Ae + 
YeGe KSectton § .of Pvopehae antenna» ii | 
For particularily Ereay Loaws tne coupressiog zone may also 
ce reinforced. Tne Pods sre pent At their Saas tO secure. per wi ge ark 
anchorage in the concrete ve ia pi). Ptar erable: ere also round ieee 
curved €nds. BS Great ON cues take. 


ee Hcy 


27 gen & . we eh iy 4° | m fs : 

fo receive the horizontal’ shears are provided coeae or flat he i 
stirrups (Fig. 51), that must be set closer towards the Suppo a 
rts, corresgonding to the incrase in the shears. Such ‘stirrups | 
also afford @ better connection between. rib and’ slab; ‘they are 

less necessary in slabs than in [-beams, where they. must oppose | 

shearing between the rib and slab, ‘besides the usual addi tion 
or an arch at the transition. With bearins rods. arranged” in ji ae 

pairs, several stirrups may be placed beside each ‘other de He 


; Pee wt 


that each pair of rods in a vertical sah a digek go 


ome 


Hib 


eed rather express. architectural ‘than statu ‘ 
it any ptveae form ot ground area Ae be 0 
E. 


te beams Bair oeere ‘aisah on their pert so snot! 


4H 


tloor of a water tower. fhe 8 piers are: exteraally ‘connected 
by a Continuous ring outer beam. he 3 
Pig. 55 illustrates the use of the) ‘pilin ginger. concrete. t a 
tloor. The supports nave octaconal sections. Dimensions andy ay Pe Bos 
ata for caleuletion are evident | in) the: illustration. The starr 
rups are 6 to 7 mm diameter. 34 eS a 
‘ one desires to econonize material and a RY deoths £3: 
tor beams of particularly great span or loading, then may be 


employed double. beams as in Fig. 50. (Also” Bee) dary ), “e they 


ed) 
Sc» 


Ot A ate ", 
ae ee we os 


my a Slama rf 
are: yy ud 2 


+ 
& 
a ey 


u 4 
ee Ua 
De byt 
aS al c 


4, 


3% A coffered ceiling in reinforced concrete produces a good © 


a¢ 


28 

will fall on the window piers and save the beam, that would o 
otherwise fall on the window lintel. Thus the coupled beam may 
act exactly as a whole,and one may employ a Rabitz span as sh- 
own in the Figure, which also produces a good transverse stif- 
fening. Otherwise are advisable separate cross ribs at certain 
distances for stiffening, or wooden timbers as in Fig. 34 b. — 
Another example of a divided beam, here conceived as a termin— 
ating ceiling next the attic, is presented in Fis, 57. | | 

To lessen the thickness of the floor at tne middle of the r 
room, and to produce a definite plane underside | ’ ‘that is sui-. 
table for stonecutter’s work later, may be: assumed as in Fig. 
58 various heavy panels, cinders in the middle bower. part(800_ ey 
xil/m2) and gravel sand i: the side ganels..Gravel sand at — A Lae 
1600 kil/w2. In this manner may a complete fixing of the- middle er 
peam be obtained, even if no wide compression zone exists, HT ats ee 
in spite of tae live load of 500 kil/m and the span phoanbiab eae oes 
to 10.2 m. The lacking compression — gone’ is replaced py a 2 corre : 
esponding compression | reinforcement. - ees 


A. De8G. SAe DoutsSe Bauze Genent Supplement. Lede edd we an z 


ornamental effect; it further ellows an economical “ase- of mat~\ 

crials, and may be employed for rooms of any size. The variet- 

ions in decorative treatment are unlimited. The supporting bee ae 

ais are mergty: arranged in one direction as merely blind,--‘or x 1 ae 

wnat igs much vreferable and is very advisable for an ‘approxin- ey ae a 

ately souare plan -- are arranged in both directions. to. trans- 

mit: the load. Tne reintorcement ocurring in one © panel wild. bee. 

combined ‘in the ‘rib. concerned, so that cach rz itself. reppessyt 

ents a T-beam. Ii pespecially characterestic motives are selec— 

ted for the coffers, then is recommended 4 previous preparation a 

5¢ the slaos in plaster moulds.(Pig. 60). gat wa a ae URS ate 
Figs. 59 and 60 show the treatment of the ceiling of tae Sank oa A 

vine Bank of the third German Hxhibition of Art industries Pain it ne 
resden (Dyckerhoéi & Widmann Co). All. plastering or covering 

is avoided, the ‘ornaments are made bf the sculptor. The cotfer | 

slabs were mage in Gypsum moulds in phe workshop with adcead'g — 

cilaed mosaics, recognizable in tne picture by the effect. of 

the lignt, and after washing witn dilute moriatic acid, were e 

set between already prepared Supporting ribs at the building 

Site. Mixing .proportions 1. : 3:4. Erelininary mixture on the 


So 


37 


29 
visible surfaces i: 3. se 
At the néw Railway Station in Leipzig were employed rectang— 
ular coifer slabs as in Fig. 61. They were tamped ready on the 
groond, and then laid in the rebates of the ribs. zor the pur- 
pose of setting served two loops at the outsides. RixtiE prop- 
ortions 1 cement * 3 crushed. dolomite. 
®xamples of forms“of coffers in place in the framework are 
snown by Figs. 62 to 64. Another example is represented in ia es 
05; the covering of the great auditorium in the new College B 
ic of the University of. freiburg-i-f. The plan. ‘BE. ‘the- Cys 
ceiling is an ellipse 17.6 * 23.6 m. Live. load 500. kil/uts he ge 
ere was chosen a cofiered ceiling, with: intersecting T-beams. OP Baek 
Tne reinforcement of the snorter spans £0 straight through, W i. 
while the rods ‘of the longer beans. are led at ‘the intersections — 
over those of.the transverse beams. On. account of the reduction 
or the eifective depth, enlargements occur a4 these intersect- 
ions. fhe ceiling is enclosed ny a Separate bearing’ Ping: beam 
90 cm nigh.”+ | ee aa me ee 
Rote Le Pe 38-6 eavknns See Deuts. Weis ree ty AML Ped 
In the rebuilding of the Museum for ithnology in ‘Hamburg, © 
coffered slabs of reinforced conerete were made. On! the ground, 
that on the lower side exhibit the desired” architectural forns 
on the upper being the necessary form of the top. (Fig. 66). # : 
These coftered slabs were 2 on thick ee ‘the panel, nd reser 
ed as reinforcement a wire netting of 6 mm Ry Be and 400, an 
aidth of mest. The slabs were produced in. wooden: forms, that 
vere internally covered by tin. The cotter slabs’ later formed 
the centering for tne Supporting reinforced concrete. floor. | 
The method here employed can be ‘properly recommended. — yin 
Note 2. pe8S. Burthen, see B& B. 1044. p. 249. oe 
in dwellings ana commercial buildings may be employed for 
obtaining a plane under surface light: Rabitz, Bacula or a 3 ak | 
ceilings, also stucco covering and gypsum boards. A ages | | ee 
Necessarily the beams can be: omitted at top. For example, RON a, 
rig. 67 shows’a construction, wnere only the side beams are) 4 
omitted at top to obtain tae under surface more ‘peadtiy) Maree 
6. Construction of floors. with epeatal steel reintorees ae ean 


Mente > a ae ‘ ce , eet ys Sa ae 


Floors with. expanded metal. By expanded metal is) ‘understood By eae 
a network with fixed intersections stamped | from dering steel (or cae 


other metal wit eo a hy 


4| 


30 aaa 
“ther metal without loss of metal (Fig, 68). The expanded metal 
1s made with 6 different widths of mesh in sheets of very great 
length and a maximum width of 4.5 m. ; 

for small spans (up to 2.4 m) suffices a simple plane reinf- 
orcement irstead of the otherwise necessary, bearing and dipia+! 
ion rods. To the constructor is then given the certainty, that. 
the reinforcement ‘is statically eifective in all its parts. M 
Moreover this 1s 20t dependent on the skill. of the’ ‘workmen in. 
the same degree aS with tne use or round rods. 

Fith expanded metal sheets for ‘greater spans the: resulting © 
tensile stresses are divided between tro reinforcements. placed — , 
above each other, or indeed a portion is. taken by a reinforce- 
nent of. round : bearing rods, which ron. paral el +0 the width of 
span, and the otacr ‘portion of the stresses by. a reinforcement 
of expanaed metal lying above the rods. Tne latter produces a 
distribution of the compression over ‘the entirel slab in bota 

directions, thus corresponding | to the otherwise stated usual — 
distribution rods. Since the ‘band-shaped strips of: the” pane er 


ed metal are bent at an angle, the ‘strips. form a support. ek LNs 


the concrete and so enclose 4%) that all: slip: ais. excluded. 
vne construction Of }an.’ expanded | metal » floor with bearing 
rods proceeds as follows:-- first the rods. are. placed on the o 
completed centering. The rod endsat the external wall. fame) sy 
bent around a flat par 5° 40 um, and this. flat par. is. oer 
to the wall at each/1.5 m. If the’ floor | be supported oy ats: 
then the bearing rods are hooked over ‘the flanges” (Fig. 9). oe 
Thus a complete enclosure or the? rods by the concrete occurs, 
and there is best laid between this and the centering ae nn ae 
transverse rods (also bits. of wood and concrete) at distances ) 
of about 1.5 m, on which rest the round rods. (Fig. 69). ‘After | ‘* 
the rods are placed, then comes the expanded metal above ‘them, 
indeed so that the longitudinal direction of the meshes: “is. el 
allel to the rods. ; we SN 
Expenced metal’is euployed with advantage: in ua} Foxe of 
tloors, especially as a substitute for the distribution rods, 
but then also as a supported plaster ceiling, sham vaults, for 
covering the bottom flanges of ‘beams, etc. (Fig. 3). Hi 
Fleors witn Kahn bars. fhe Kahn bar | invented in America is. 
now Comune into use. with us more ana core. fhe bars have. the * 
oss sections given in Fig. 70, and are made of ‘the best. mild 
teel 1. They are} nite: in tae up to. a oF Me ne £ 


ay 


S 


pe 


n 
if 


>; yeaa 


Wo. 


i 
tliat tlangses at right and left of the nucleus are cut as reou- 
)red on special mechines, and are bent up at 45° as stirrups, 

in Pig. J1. Simee they are still.connected to the nucleus, 
no other fastening is necessary. Any slip of the bar’ in the 
conerete is therefore excluded, and therefore any attention 
to the bend stresses is here unnecessary. The occurrence of 
gabive moments is provided for in a simple Way as” in Pig. 
72. fne bars come to the building site ready to set; the leng- 
th of the bar as well as the number and length of tne stirrups 
correspond to the statical calculations. Naturally isialso.sa~ 4; 
ved the arrangement of additional stirrups. ‘The Kahn» reinforc- ay 
enent is suitable:for all kinds of floor construction, sections 
A ana.B being particularly for. floors with nollow blocks. CAT . 
so see Pig. 73). By the German Kann-Bar Co (Jordahl & Co, Ber- iy 
lin, the following sections are supplied to the trade. (Fig. 7). 


ne 
ne 
ny 
Ze 


, ’ 
: ib Ay 4 
vers 
ee, 
2 


Section. Weight per. Area ot section ‘in on? es he if 4 
mlin. in Solid ae Without epee a 
ECR ha ad aban a OC re a8 
B Gi863 2) Oz70 Nie Re ea ee ae | 
Mee 106, Ph ig OP ae Se Ne ay ay 
‘4 2600 2 WEDS) ASAD 7 A OA he , 
tl 4.00 5 440 Wis) aa ns “0.88 . Oy ar 
Til Tear Qube, 7.70. oe $0 patho ee 
IV 10.00 12.78 10.28 a may 23) Ny 


Note 1. Pehle The strenéth of. ‘he. enka. steel AS. exes ok 5000 
+6 .S5O0 ‘Kibl\ow? * Ahernefore. veins substantively areater. shan, <) 
thot of the usual commercior roads. Bence | shere has a\so. een 


alvowed for o Long time 0 peraisstole stress of 1.200 KALlon” Pek. 
Pohlmann syste (oulb steel floors). These. flcors sre veonst= 
racted by the aid of the So-called.‘ ‘bulb. bars”. “These are bars 
nite ‘sections like railway rails: wita, perforated websi5 to 17% 
em high. (Fig. 74). 4 The vonding is eifected by annular ghee 
rups or slings, that pass through the holes as. shown 1D Fle. ye 
75, and for larger structures are fixed by iron wedees. 
KOte® LePe Ase the ovrvevnar form of section wos somewhat arty - ; 
erent (PVG. T6)3. this disc shod ‘Betadonah uoledr wal te the new 


Ne 


form shows trVangurar holes im. the wed. sh * 
The weak upper flange of the bulb shape rises into the upper 

zone ~ ovherwise the bars would be set and enclosed exactly 1 

like I-beams; the construction of the floor between than aawe= 


eeds in 


m4 


32 ) ae 

proceeds in the same manner as between -I-beams. the: framenork , 
furtaoer receives a strong support by the insertion of the str- 
ong bulb shapes, that are able to receive the frameworg and. c 
centering, aS well as the fresh concrete and the effects of BS 
the process of construction. Only for very preat spans is nec- 
essary a support at the middle of the shape. : 

From Figs. 76, 77, the arrangement of a nutb-knape. floor ‘is 
apparent. The intermediate slabs are reinforced in the usual 
way by bearing a and distributing rods. By its holes) and. stirru- 
ps, the bulod bar is connected to the “upper zone of the: concrete, 
by which the aera nd teh necessary stirrups and ‘bent ZoUs are. Pen 
placed. | ew We Om hoe ae 

Leschinsky system. Here the. chiokvels is also to. select so ti 5° hie de 
the reinforcement of the beam, that: itds able to. receive with | A a 
certainty the weight of the framework and ‘centering, of the cea 
concrete and the effect of tne’ building procedure,. for this 
purpose an I-beam (mostly I. N. P. 10) 3 adde: the 
rods, which will also be sufficiently ‘strong, bat it may. alone ie 
Mites the baa Maui = snears to. ‘the ‘SUPDOD YS Bie. ae shows whe me 


ig Pe 


Méiler system. (Fig. 99). The compression gone. is rake Bkaras - 
by a concrete slab, which ‘is made thicker next the abutments, 
like a vault. From this slab .prajects aownward a) curved PLD 
ine reinforcement of this consists usually of flat bars, gece 
the ends of which are riveted angles, so that the horizontal — 
stress of the caétenary reinforcement is transferred to ‘the sree 
as compressile stress. Side thrust against the wall does ‘not. oe 
occur; one only has to do with vertical pressures. The ‘angles ; 
riveted to tae tension bands near the supports make unnecessa- 
ry any attention to the bond i aheay. 7 ie concrete aod a. 


steel. 
for greater spans and ied. the floor slab is baths reinf= 
orced further by I-beams or round rods placed at right aneteey 
to the ribs, so tnaat the effect of concentrated loads may be 
_aistributed to several ribs. In order to make the. entire arch- 
itectural form lignter, the webs may be perforated. ¥ girders 
re arranged, then @ “connection a tivo Crossing: rods is. s produ— 


which often results ino considcravte Vengthening | of. Ane. time. oe 


33 
produced by fastening the last anchor angles ‘adetien' with 5 
mm wire. 

For dwellings and commerical buildingsare possible Spans of 
1Z m. The calculation of the floor proceeds accopdings to the 
theory or the T-beam.ihe Méller girder is certainly most Finda be 
uently employed in bridge construction. + 

Nove 1. pehos See Kersten. Beam Bridges. 8 ra cdition. 

7. @eilings of glass and concrete. 

for skylights in glass and concrete, the otherwise usual » ree 
ames and ribs of cast and ‘wrought iron are. replaced by reinfor- 
ced concrete, which is combined With the glass priszs ‘into a. 
ereat solid slab. Numerous tests and test loadings have | proved 
the suitability of such constructions. ‘Exposed iron’ parts, that va 
might rust, are here absent. appearances of destructicn. ‘in con- a 
sequence of unequal ‘temperature extensions of the. different CN mre Ce ws 
nateriels are not to be feared. A separate cost for contempor-— cet a ee 
ary or repeated . painting: vanishes. Farther advantages: are. ‘the 
sreat ‘resistance. to ‘Chemical decomposition, the high strength — 
and resistance to fire, as well as the: generally. small. cost. in 
comparison to skylights in cast ‘iron’ irames. 2 The glass-cone- 
rete construction. car be graduated in depta and strengtr acces” 
rding to its purpose, as well as to the. optical principles. to. 
cé considered. The manufacture of the élass-concrete slabs. may” ee 
e1ther occur in the workshop. -- for small dimensions 0 or whe oe 
ere this is not possible, at the building site. Lice as 

Note 2. Ds AS. Lvon-framesiuas a rule ust ve. specially made, cay 


i: aa 


Tor delivery, and of rReges\ SELPENSES ° er o\terations of patte~ 
rus for cast Vran. * aye 
Quite similar: are the Solfac-glase-concrete ehidaean: ae the 
General Star-Prism-,o, Beriin. They have a great capacity of “e 
resistance to injuries and afford good lighting. Fic. 80 shows - | 
the mode of construction of the Solfac ceiling, the support on oe 
i-béams with @xpansion ‘joints, and the bedding on a reinforced — | 
concrete girder. As a particularly effec tive and harmonious c 
covering of the room may | be employed crystal clear and colored” 
class in appropriate arrangement. Pig. 81 gives a section thr- 
ough two Solfac panels, such as have been recently introduced ‘ 
in the trade by the Co. mentioned. The external surface of the 


case 18 grooved crosswist for better bond between concrete and - 
class. -- The mode of reinforcement for ne Solfac sapanny: hits : te 
ees: 


vantageous .o transverse sabes weante! ‘the tne 
ice of bau German he as (pein or 


crete. . 


ay 3 


colygonal sections” are e 4 ae 
are more complex and “ore dearer. | 


the eross ‘section; in pall | cases | there nus 


Support. 


ae 


a 


48 


50 


35 


Xote 1. Be4T. To SO Kelow *hHis HPercantage he: ENTGv mp eee. 


advantageous, an the other wand with too greet a steel aren, . 
she cross sectian of the concrete woudd be t00 small, ond acce © 


orainely the danger of buckVing would be nore ooethin eeeek enue 


The arrangement of more than 4 supporting rods is ofepracti- 


cal use only in particularly sreat sectional areas. The inter- 


ior of the support may be made nollow if necessary by the ins- 
ertion of a suitable guide pipe (Fig. 85). Naturally such a ~ 


reduction of the section reduces the bearing capacity. The st- od 


rengthening of existing iron columns may be done in the manner 


evident in Fig. 66; the cross colum is fireproofed, but at the. 
same time is made stronger and more secure against buckling. Ef 
The angles of the pier may be protected frog injury by angles: 


as in Fig. 87. 
To provide against the bending of the separate roas and te: 


fix the reinforcement during the tamping, at distances of 20 i ee. 


to 50 cm transverse connections by round wores are provided. | 
(Figs. 91, 92). These wore bands may be variously arfanged. . 


The supports introduced by Considere, the spirally hooped SAE 
le 


(Fig. 83). Thinner and closes spirals are more effective in 1 


crete afford the great advantage or particular Slenderness.. 


this use of steel, than thicker spirals with hisher turns. Ta 
opposition to Considere, Abramoff-Magia place the hoops here . 
not in entire spirals, but in several separate spiral connect- 
ions between each two longitudinal rods, which thus as a. whole . 
likewise form a continuous hooping. (Figs. 89, OS) 3c es 


Kote 1.p-48. The usuose reinforced concrete supports ore a 
erably. thick in contrast to Vron columns, simoe the. safety tes \ 
a 


‘ es 


quired by the Prussian Regulations is revortipery Wibe 
if the supports extend through several stories, then’ is. the» 
cross section to be reduced upward according to the reduction — 
of the loading; this causes a stopping of the reinicorcement, oe 
as well as the use of pieces of gas pive 2 at the abutting ends 
of the steel rods. (Pig. 91). Bc 
On spirally hooped columns, see Part I. Yet there hee suffi- 
ces for connecting the rod ends a winding with wire as in Pig. 
SO, The abutting of the longitudinal rods is not placed in the” 
‘lower column (Pig. 95 a), but in the upper column if fossible | 
(Fig. 95 b), where the rods extend 20 to 30 cm or more above 
the top of the floor. 4 : 
Kote BSepe-4B. If the prers (with excentric forces) ane. anne 


io 


Se ae. ae see 
r Deets ss ae 
2 aeth fae 2 Tt se 


angi 
At 


rs 


A e 
a ¥ ‘ “yt \ s yt by 4 + 
: \ i ae . Ae Stall 
86 a, Five te. eet a) , 
: - AeA a ey | 


=] 
db 
@ 
Q 
2) 
=] 
mB 
@m 
Q 
ot 
j- 
2) 
te] 
o 
ry 
fou 
0) 
o> 
4 
72) 
=f 
4+ 
et. 
a 
et 
Ss 
a) 
a 
a 
M2) 
i 
a2) 
ar 
ct 
Bh 
Se 
mn 
ot 
— 
ee 
a 
ee 


and beams fo a united whole and. they aia act ‘together rae 
ically likewise. ‘Another. example yt which tne upper pier is. Bo 
set as if pivoted is given in the ‘eucceding Fig. 92, Connecti- babe ao 
ons of beams with particular architectural ‘treatment are shown ei ee 
in Figs. 93, 94. . PN ead ‘ae Pet en, ae ae 
4s for the form o. tne base of whe e colony, there are to be as 


pile ecnca town) his makes | ease arger 
presage all: sia as in mp yr in Poge 


enna we 


ay a s ihm cet ? 


NOCS? is Ped2>o See. the Section on 
cavoubated | example | Ln the appendix, 4 
Sometimes supports of Scnleuder conerete < 
i01 vo 403 exhibit such a sortreneetaeeisi. =f 


sao 


on is constructed es NES, ‘phen: “tag. skeleton ith | 
dition of concrete furring strips is” placed in the w 
(Fig. 102), and in this the accurately measured. pias: af! ua 
crete. By snaking the Recerca one finale age cag 


section shown in Pig. 103. fo make . possible a better beavarg 7 Be : 

with tae shed trusses, a number of rods were already | Placed i a 

tee nead of the column, that praject about 60 cn. 

MOCS 2eHed2%e On shaken concrete An Senera, see Part 1, 

,fter the removal of the forms from an ‘ordinary square pier, 
for any reason a later increase in the cross section is ne- 

ssary, then the old column may be covered by reinforced con- 

crete, @ means that may aiso be employed with advantage, when — 
already existing column is. too strongly stressed by an. nin- 
eased loading. | Pak ae RE it 

C. Division and Hxternal-Walis. 2 Poy oe ee 

AOVE 140-58. On Veotated walls, see Section ee 9 it Bae Ay besides 

eee the Sections on Vater Leputmenitnahe hth Silo | ‘structures. ‘ona Ret 

oleae Hove. — ea FN ‘ Hae 

‘a€ use of internal and- ‘external walls reinforced § with steel 
ents many advantages (st ‘building. construction; they are: s 3 

sats + ageunst tire beat eisai are hilar ae Rieuione! 


ed 


Q 


oo 


~~ 


ging 5 to 8 cm and’ hae): In: ‘consequence of their Shoe 
ss taney ities 80 dimensions of: rooms. They possess: 21 


vite surfaces. (on this: see Part 3). Beatty stack Pe 
stucco ornaments, marble slabs | and ee like, as. pelt arg ; 


tne wall may ey tampea With Cinder. ‘or pumice. conerete 
may later be cut and pandded PY the ‘Stonecutter Like 5 


dear ‘on acconnt or the. pongid sewn cost or the: spine 
are chieily employed only in factories and warehouses. For 
aweéllings they are so:far disadvantageous, as they form bad ‘ 
conductors of heat, and in certain cases aid: in increasing the | Ad yk : 
Gampness of the air, Further the: insertion of hooks and nails ea 
is only possible by the aid of stone drills and wooden dpiaces Laeger 
n unfinished condition without plastering, they have a bad a 
opearance, wherefore they often receive a facing of bricks. — 
Since the verticel load of the wall is in great part very small, 
orick masonry is best recommended for a filling beaucen) reinf— : 


orced Concrete piers and ; Jambs.. (Fig. 196). 


38 ! | | 
In such cases a thickness of bricks at 1 brick is ta¥en, since SUE a 
otherwise the cost would be too great. For a filling are also , | 
employed cinder and pumice concreté, or cement slabs that can 
oe nailed, which are made at bhe building. ‘Thereby the cost of 
the building is often reduced ig, considerable emount. Doorw— 
ays and windows can be enclosed in reinforced concrete. walls 
by timbers as thick as the ‘wall, or by. channel bars. The rein- 
forcement ending at these ‘enclosures is to be strongly fasten-_ 
ed to them. To receive nails serve special wooden pret, thet 
are bedded in the concrete. (Fig. 105) 6. Gp eee Mee LIN 
Note So Pe RSe.Wolls. short ane RO Loaded Woy, be ule of cinder 
or pumice concrete, and wid. then yeceiwe NOABS. « 
Resistance to sound and heat may be obtained by. the construc- 
tion of double walls with acllow spaces or filling; or by cork | 
or corkstone covering (particularly for external walls). Men - ppl Ay 
also employ wall coverings of specially Ureneres felts, unica te a aa Ww 
then receive a layer of reeds and plastering. eke tae ae ee ee 
ionier walls, according to Fig. 106, have horizontal pearing | 2 an 
and vertical distributing ‘rods, that intersect at prigat angles, 
and like slabs have their alternate. intersections. connected by 
wirigg. As a rule only a network reinforcement: is necessary A 
the midale of the wall. if bending stresses. ‘also. occur. (by sh- 
Pooks or: wind Presses), pe ree: of tw, netnoris (3s, ads. 


intekneas id ead: panyeeel on Been sides ‘sion’ 5 fe 
connection to masonry is: obtained by allowing the horizontal — 
cearing rods to enter it about 10° em, In such cases one ‘aies 
in consideration the location of ‘the joints in arranging the 
network. In the construction of hollow walls, there ster, 
an internal thickness cf 3 and an external one of 5 on, with 
me to 15 cm apart. Tans : | Sah Sa i gales et 
arger bearing walls are shown in. . Figs. 197° to ; 408. “he. fire. | as 

st ae explains the special reinforcement Suitable for + 

a doorway opening. The Monier wall -represented ‘in Pig..108 is- 

30 cm thick, 4,20 m hign and 14 m span, and it serves, to. rece~ 

ive a floor load as well as the ends of walls. and ceiling beams. 

The bending moment amounts to 355 m tonnes. fhe ‘reinforcement 

is doubled: -=,i, = 95 om, cg oR Se 2 cm. A division wail cons~ 

tracted as a  satakonnes dhaesate trussed girder furnished with 

inclined and vertical diagonals, likewise | with the attached 


dae 


ccéiling 34 om deep is Shown 


mA 


Waray" 
Seale ah 
pec 


SS 


st 


39 | 

ceiling 34 cm deep is shown in Fig. 109. The total load anon te 
to 230 tonnes. Tae wall exhibits three interruptions for the 
insertion of intermediate doors. The wall girder rests on two 
reintorcea concrete piers, and it is itself bedded on lead pl- 
ates. (Further see B & &. 1911. p. 397). 

Wooden doorway lintels(and frames) as in Pig. iiz have the 
disadvantage oi swelling and warping, while the usual channel 
bar frame of the doorway affords no seeure fastening. Prefera- 
ole for thin reinforcea concrete walls are door frames of spe- 

ially rolled sections. Fig. 110. shows such a door frame, such 
as are supblied .py the Special Rolling Kill £, Mannstaedt & CO. 

Tae Usna idea of the Rabitz syster a is to secure the stren- 
eth pf the wall by stressing tne network in its middle (i mm | 
@ire and 2 cm meshes). Id the walls have a considerable length, 
then are also provided special means of stressing. At the con- 
nection to masonry occurs the fastenings of the wire network to 
wooden dowélls of dovetali shape, which are let into the Mason _ 
ry. Instead Of the dearer conrecte is usually taken a mixture 
of lime, gypsum (up to 20 per cent), send and size. When the ms 
coating is applied to one side, it is then held :fast in the m 3 
meshes of the wire, and then the other side “is. coated — before 
it sets. These Rabitz walls are made single 5 cm thick)» ‘or. d” 
double (each 3 cm thick with a space of 5 cm). For the purpose : 
of2 setting hooks for clothing and pictures a continuous wood- _ 
en strip is fastened on the wire netting and tegen plastered 
with 1b. ets ie rae a a 

Note 1.269.564 See Kote an Pe. Acs “ene Radite aol oh dela : 


erly HE VAT OFGOS concrete, out Ve wenrtroned Vn view of ‘vee Trea- 


went use Wn yeinforced concrete structures. the ‘some As. Aru 
of wirertive and of expanded wertar wots, OS | werd 08 ay ‘the 
brick wobls veinforced with stecl.. Pty te : 

The construction of wire-tile walls shows the same apousd | Fe ya 
idea; tight stressing of the wire network 2 at the ‘edges by h bi Hs 
nooks. Also here cement plaster is but seldom used, mostly a aoe 
mixture of i gypsum.+ 2 lime moraar. (Pig. dil). ae 

Note VeHeSG-. SOe.NOt]S| AN Pe Se 

fhe construction of expanded metal walls weeny as: feliatel 
in wooden structures the expanded metal is nailed directly to 
wooden posts or boards, and is crossed at distances of 50 to 80 
cu by 5 mm rods. On the steel structures these rods are fast- 


0 i, nak 4 


iy 


rg 


ine Toy | | 

fastened to the flanges by clamps; “the inddaod metal is attin 
ached by wire loops. If neither wooden or steel framework exi- 
sts, then is first constructed a skeleton of steel wires and ) 
tne expanded metal is attached to this by wire loops. Ordinary yy 
toickness of wall 4 to y) em. As mortar is to be recommended t _ 
the so-callea patent mortar, lime mortar with ZO p.c. éypsun. 
Pig. 112 exhibits the door §ambcof sucn a wall. 

Particularly suitable:tftor acricultural buildings are the ine 
ick walls reinforced with steel according to the Prts system. 
These are composed of vertical and horizontal bands 25% Le 25. 
ma stretched beside each other in two different planes, whose 
distance apart amounts to 53 cm(?). The rectangular panels th-_ 
en produced are walled with:porous bricks set in cement mortar, 


indeed so that the bands are entirely enclosed ‘in the cement. 


by the intimate connection of bricks, stecl and cement, the w 
wall is in condition to possess a good fesistance to. side pres 
ssure, free between supports. 
Fig. 1135 exhibits a varied walling of the Sidei ‘bande; a 
a trapezoidal brick, » = a wall brick seit on edge, c= slabs). 
of stone bits, d = gravel concrete slabs, e = face bricks. e 
Fig. 114 shows the construction of a hollow block wall. and 
indeed here is concerned the walling of. the work: between ‘rein- 
rorced concrete piers and beams for the new Boat House of the 
Imperial Wharf at Dantzic. + the shape of the blocks is evident _ 
from the illustration. They have at the middle a full and at. 
each side a half groove for mortar; between them lie two. thor 
ow spaces. The blocks are set on. each other; that the ‘grooves . 
form catenary ‘channels and can serve. to .receive. the steel rei- 
atorcement in both horigontal and vertical directions. The le 
ngth of the hollow block is 51 cm, its heignt being 22.5 ome 
The manufactoure of these blocks proceeds in ‘special torus in 
nand machines. St heat ae 
Note 1. 0-98. See B & Be. 1910. .- 43. 4 coef 2) eat 
As an example of the increasing use ‘of the ‘hollow: block sys 
‘es attention may yet be called to the Schnell system repres- 
ented “in Fig. 115. ‘Lhe masonry is: composed - of separate sneviae 
vlocks, whose side can be varied according to the thickness: of 
tine wall and the thickness .be changed according to. the compres-_ 
Sion stress. The setting arrangement of the blocks. is evident — 
from the illustration. To receive the floor, the wall is cover- oa 


ok 


41 / 
covered by slabs. The connection of the masonry horizontally 
can be secured by flat bars, strengthened vertically by the c 
concreting or filling the certain hollow scape. If an internal 
wall be desired for nailing, there may be used for this pumice 
or cinder concrete, the resistant gravel concrete being for t 
the external wall. Further see B & &. 1912. 7.378. 

Recently have been employed also hollow glass buildings blocks, 
Falcenier patent (Glassworks Adlerhiitte in Silesia), which are 
just as suitable for yalis as for skylights.(Fig. 116). They 
are set with stretched wires and concrete, thus Saving a Spec— 
ial framework, and are no dearer than double windows, but ind- 
eed are more aurable than those. ‘They. are always clear and li- 
cht, and form an excellent protection from heat and cold, damp— 
ness and noise. With (stdtay a safety they possess a résistance 
to compression of 16 kil/oné, and can be set up to 10 me with-— 
out special stiffentne. | we 

A glass filling in the system of the German Luxfer-Prism Syne 
dicate of Rerlin is given in Fig. an Fa 4 
D. Statrways. . . Woes 

Stairways of reinforced concrete in ‘the first line pecaéa ts 
the advantage of greater safety from fire, At is) well known ia 
fires of importance, that the stairway. should remain usable as. 
long as possible. Stairways of iron and stone without, Rabitz, | 
60 wire-tile or expanded metal enclosures are soon destroyed | by 

fire, and are even more dangerous than wooden stairwayu, that 
can then still be uscd, gyep if aifesay eh fie: Granite and 
sandstone explode too quickly, “~ and steel in ‘nost fires” expe- 
riences an entire destruction in conseauence of the heat pro- 
duced by the glow. The glowing parts ot the steel | cannot be ae 
passed, bend, and by falling produce not ‘only a general. hea 
truction of the adjacent masonry. All these disadvantages. are. 


prewented by reinforced conerete. The construction of epson ~ 


enclosed stairway halls, a requirement of perfect safety from 
fire, is not necessary there. 
Note 1.p.60. Also seetReport on dander {row {ine for stane. 
saterkots Ag .staseeayest® & be MOGs Re 210 le meee yehoai ms ka 
129056 Be ASLs | | ihe 
Another edvantage of reinforced concrete stairways is their 
unlimited forms, the possibility of adapting them to a plan, 
nowever developed. Men build stairs fixed at sides, widely .pro- 


jecting and suspended stairs, as well as. winding stairs. 


2 ee 


z 


& 
es 


; 


a 


b/ 


A2e 

bifficdlt stonécutting, is avoided, 

The arrangemént of the stairway may be made according to dif- 
ferent points of view, according to the neture of the vlan, the 
form of the axis, the mode of construction, or even according 
to the purpose. Indeed best: ‘1s the arrangement according to s 
statical points of view, and according to the mode of construc- 
tion. | 

Tnere are distinguished: -- 

1. Free supporting stairs with steps fixed at one end ero. 
1B) | 
Bach separate step extends about 25 cm ‘into the wall . and 
is to be calculated as a beam fixed at the end with tee Aba 
(f - 2 em) + and the preadth b. The steel reinforcements lie 
in the upper zone. The fact that each step rests on the step 
next beneath, sc that to the lowest step is transferred the 
entire weight of the stair flight to the landing beam or phe: 
floor, is to be neglected in the calculation of the separate A 
steps. Only in the calculation of the handing beam will this 


4 
4 


Meme et 


condition be considered -- in view of the frequently not enti-— 
rely admissible fixing of the step in the masonry. More unfa-_ 
vorably than 2 unifornly distributed live ‘load (at most 400 | 
kil/m2) is the effect of two concentrated loads of 200 kil ‘i 
each eb the ends: ot the step and 50 Ch apart. lonent: uM at ‘the | 


tixed ena = Qt, 


Kote 15 Pe Sie ACCOTAINE ‘to soviger,, ‘Shene, ie, token a = oo Sone 
The landing slab extends from the wall to the landing beam 
and can indeed always be calculated with MF ===, assuming: Laan) 
shall spansAt the support at least: half the. réinforcenent. te! 
to be bent upward, and especially nt py well anchored in the 
landing .beam. | ele eang 
The landing beam, freely supported | at both ends in ‘the wall 
nas as its loadingy-- — : 3 he 
a. Dead weight of the beam: tuaene: | | : 
b. Dead and live. loads of half the landing di abiisesedsuy : 
floor and plastering. 
c. Dead and live loads (about 400 kil/m+ of floor area of 
nalf the ascending flight of steps. 
This load then acts on only one side of the beam... . 
The beam is to be calculated as a T-beam with free ena supp— 
orts. But the slab extendas on only one side. Some of the rein- 


bf 


FE 


| 
43 
reinforcement might be bent upward at the support, 
¢. Stairs with steps freely supported or bartially fixed 
Steps. 

the calculation of the steps follows as for uniformly distr- 
iputed live load. (Fig. 119). ? 

3- Stairs with flight slabs in reinforced concrete, that 
extend between landing beams. (Fig. 120 a). 
* fhe steps (of tamped copcrete, Sranite, or the agit are set 
subseauently. 

{ne landing slab is here fixed at one Side and mast ‘ais be 
connected with the landing ‘bead by an arch. Mo= =-- to --- . 
Vomplete fixing only occurs if the slab is also. entirely ‘fixed 
in the wall,(but which seldom occurs). 

For the string is taken as Span the horigontal distance bet-— 
ween centres of the landing beams. fhe connection with the lan- 
ding bean is also to be by an arch. The. negative moments are 
sufficiently provided for by a. corresponding prreneeneR ioe fe Ra 


\ 


the reinforcement. Re mye ne ca BS 
Set Stairs with Ache beams of, réintorced | concrete. (Fig. ee ae 


The stan extends from string beam to string beams) ee ae ts a ONS: 
The string beam extends from landing to landing and. is. to. be | ee 

calculated as a T-beam with slab at one side only with. the. ave ieee 

erage depth 1.4 d. The effective Lepgth is to be measured ‘on nae 

the plan. ee ee 
The calculation of the other . structural parts proceeds” as. pe 

previously stated. et eas 

5.Stairs with slabs of EN i: forms. Bat 

Here only approximate calculations. are possible, _ ‘ | 
In the following will be more Tully described the different 

kings of stair constructions in reinforced concrete . aM haces : 
Steps of reinforced concrete, as a rule, are made in factor. en a 

ies, are cheap, and can’ be. promptly delivered in all current Me es St | 

dimensions. They are cheapter than steps of cub stone, and may _ Lae, a 

ce made suificiently résistant to. wear by 2 separate covering 

of oak, artificial wood, “ tborsament 7h, terrazza, marble or 

linoleum. Otherwise a specially rich mixture (1°: 1 to 1: 2) 

With an aggregate of special resistance (granite, basalt) is 

to be employed as a facing. < No coarse sand grains may be vis- 

ible on the top surface, since such would quickly be broken 


out in the usé of the stairs. ‘The angles of the steps are 


-- a4 
rounded, aré protected by anchored angles, or by the stair cor-. 
ner bars. Fig. 221 shows the use of a Nanstadt bar. This cons- 
ists of polisaec yellow metal, and is neid by stamped anchors 
riveted to the bar. The fastening OF tse wooden ‘covering :is p 
properly by woodcscreéewe inte: previously inserted wooden plugs.. 
-, 122). warble or granite slabs about 4 to 5 cm thick are 

fastened with putty or trass mortar. A fluate coating of the 
side surfaces of: the steps ana drpessine the same with mallet 
and chisel can also be recommended in certain cases, es well ; 
as polishing afver nardening, by which an appearance like mar-— 
ole is produced. & separate reinforcement of she steps is not 
required for short lengths and lignt loads. But for greater 
tree len og tes ls necessary a reinforcement by roiled SHEREE + or 
petter by ‘two or more rods of 6 to 10 mm Glameter. | | 

Woke 1./ 46463. BeRBOLG Ly (Fy VONITH ortificoial WOOK. Pe We 

AO Ve Zoo. 62.. There ROS ai heen emploued wWATH $008 res- 
Ults Gn oddL tran, ae corvgrtindus for sicirs, . Lar . ore. évecthy 


usede 

Phe stets can‘now be set with beth | Sedalon shvaae beams of 
steel or reinforced concrete, or also ~aplOr freely supported } 
stairs -- wita one end fixed in the wall. “In the last case the 


steel is to be flaced in the ‘upper, and in? tne latter case bas 
the lower zone. ack oy, eee 
Fig. 123 snows freely snuawcedit ‘and Pig. 124 hae steps. sup- | 
ported at both ends. The setting of the same in. the walls Prom 
ceeds in tne same manner as for stone steps. The triangular — 
section is sufficient ‘here, but better ‘is setting with a spec- 
ial rectangular end. The fixing is ‘most certainly secured, ar : 
the steps ere set during the construction of the enclosing — kia 
walls. Until. the completion of the setting the free ends of eee 


the steps are to be supported. But since this mode of construc-. 


tion may considerably delay the progress of the structural work, 
as a rule men are satisfied with leaving recesses and setting 
the staps later. It is then absolutely necessary to secure the 
stepsin their places PY iron meane ss and to grout them: wehl .#' 
with cement mortar. 

A rule of the Berlin building ofticials or isten 19, ab i 
prescribes the following: -- 

“A, Bixed steps of artificial stone, whose bearing capacity 
is calculated on the assumption of strong fixing, and permiss- 
ion is accordingly given, must in general be constructed only 


6 


45 , 3 
during the progress of the stair hall, but cannot be added af-_ 
terwards, since later setting does not ensure a strons fixing. 

If on the contrary at the height ot all landings the landing 
beam or landing slab, on which rests a flight, be froperly fi- , 
xed by the progressive construction, then man also the Steps _ 
of the stairway be set later, where a careful cleaning and tan- 
ping of tne recesses must follow as far as possible. The land- 
ing beams are to be calculated for the stair flight resting t 
thereon, where it is assumed that half the flignt is carried 
oy the wall, while the other half loads the bean. | 

B. lf stain.tlights are formed: with inclined gs ue opobe con- 
crete ceilings beneath; the landings for them must be support— 
ed by beams. fhus it is not permissible to construct. flights 
at right angles, whicea partly form steps and partly landings, . 
as reinforced. concrete ceilings. On the contrary, no- hesitation 
exists for these constructions in reinforced concrete, if the 
turns are sufficiently asoured ‘by Stirrups | and double reinfor-— 
cements.“ | | 

Tne tamping moulds for steps made in factories are usually 
of sneet metal enclosed by strong wooden. Strips. ‘Phe. internal 
surfaces are coated witn mould-oil. Also cast. ‘iron detachable | 
step moulds are used, as well as Wook ones. Usual mixing: ‘pro 


portions are i: 2: 2 (also 1; Lit 2d gravel be mostly oe 


placed oy fine Pome’ Ay PRE steps mas be at least. a months — 
old, Before they are delivered for use. ; ey 
If factory made steps are not to be employed for any reason, 
for example in view of too long a time for delivery, ‘then must 
the stairway be tamped in place after previously constructing | 
the centering. Tne tamping usually follows only then the sae 
way walls already extend above. for the necessary” bond in tne 
masonry are leit recesses. | ree ON 
Pigs. 125, 126 represent the construction of a stairway with 
I-peams and xlein’s slab (p. 15). The arrangement and connect i 
ions of the flight and the landing bean occur in the same man- 
ner as tor iron stairs. The steps are of masonry and have wood- 
en treads. ee: Hee 
According to the Monier system, whose strings consist of I 
or channel shapes (Fig. 127), reinforced slabs extend between 
tnis beam and the adjacent wail, on which the separate steps 
are placed. Preferable is then a fireproof enclosing of the 
steel beam. For greater designs of stairs tne flight slab is . 


bs tala 
ats Pal ae 


er A 


AG : 
6 omitted, the the steps are tamped on a bearing Shab fixed bet-_ 
ween the landing beams (Fig. 128) or on an inclined Monier va- 
ult (Piga 129). 

Fig. 130 shows the construction of z} stairway with tree sup- 
porting flight slab. The thickness of the slab as d1 cm. ‘At e 
each 14 cm lies a roa of 10 mm diameter, The landing slab is 
10 cm thick and at each 30 cm has a rod also of 10 mm diameter. .- 
The bends of the steel are evident from the illustrations men- 
tioned. The steps have cement Seay de: and are bate vpn, By 
steel angles. 

‘A stairway construction with string heanet and deigracdad st- $ 
eps is shown by Fig. 132. Landing and string bea RS may be moul- 
ded. Hor this purpose, on the inside of the centering OPE (Pla ek Ee 
ced corresponding Strips, thereby producing a certain animation = 
of the visidle surfaces. Hor the same end, ti finally one may i ee 
have a stonecutter dress the surfaces of the concrete. age . : 

A similar construction (rebuilding .a community sbhool in Be a ee 
ettin) is evident by Figs. 133, 134. The fronts of the ‘steps oe a 
and the visible surfaces are made with 1 cement + 2 siftea gr- RE Ms 
avel. + The string beams adjoin the steps at the sides, Lanai A 
the dirty water used in cleaning the stairs is prevented from: Me 
running down on the strings. The form of another stairnay - ete hak 
the same structure is indicated in Pigs. 155, 136. To support 
the string and landing beams must here be arranged a Support, 


wnicn has a longitudinal reinforcement by angles. Another con- Pe i aoe, 


giruction with intermediate miheacn ok is shown by - ie as 
Note 1. p.-68. B& Be AV. sid. eA ee Aa 
C7 With the existence of a separate ‘stairway hall of pes Rare a 
plen, the stairway may be constructed with and without ‘interme : 
diate supports, as Fig. 138 shows. In the first case the steps. nh AeUt oat ae 
are fixed at the side. If this fixing be not possible for eens ee 
tain reasons, then must one have recourse to the bent bearing We 
slab or string beams (Fig. i135). ERP eS Support beneath is avoid- Rat 
ed, then may also be provided consoles for the landing slab, 
or the landing slab be suspended from points: of sunpOrt ebove: : 
1t.( reinforced concrete beam). : ! 4 
70 In Figs. 140, 141 is represented a stairway with & curved s 
string beam. Tne stair slab is fixed to the reinforced concre- 
te wall. ’ | 
A substructure of an open fligzat of steps carried down to g 


good ground 


yf 


factories, halls and theatres, church galleries, ‘Temps, ‘loadi- 


AT 

good ground and constructed in reinforced concrete is shown by 
fig. 142, (Also see B & #. 1910. p.229). For such stairs, which 
are not protected from snow and rain, is recommended a slight 
pitch forward for the treads. 

In Fig. 143 is represented the construction ic a Plight of 
steps to a beam bridge, | 

The stair railings are usually made of iron, and are bolted 
to prajecting iron parts. Wooden railings are also employed, 
for fastening which ‘phugs are set in the concrete. i aah Diam Mar Deine 

B. ‘Corbel and Gonsole Structures. 0) 8 a Be 

Hor constructing projecting parts of the building reinforced. is 
concrete appears particularly adapted. So. far. as this” concerns ay | 
buildings, there come in question here; balconies and bay oe 
dows, corbelling and entire stories, cornices, galleries. sof fk” ara 


ng platforms, corbels for crane railways, and. bhe like, Boma 
ting forms of roofs, eaves, railway halls, widened erecta, ie 
etc., will be described in anather . place. ole? ce ee 
The simplest form of a projection ° consists in “extending rhe. a3 
floor beyond the externalgwall, either’ as a slab: (with. small ry ie 
projection and light loading), or as a T-beam (Figs. daden, bee 
In the first case, care is to be taken, ‘that the slab is. not. i 


too much reduced at the edge. Ey the illustrations: nentioned ae 


ced concrete sai Meunre in the wall, are useful, with Vemiguee | 
ent according to Fig. 144 c. 3 ve” RRO re ag on 
Bote 1. pseFi. A Yule of the Borvin ovibaringe eee of were pe eet 
ah 19, AQi3, prescribes the followrnd cancerning frxed bearing 2 | 
SLVUCTUPAY VATtS. —-— “Reinforced cancrere . structures, WHOSS St- 
rength aepends more or Less upan the effectivences | of their | 
fixing a the woasanry, {or example consoles, fixed stairs, fix- 
ed TLoors, are onby pormissivbte, if. the fixed structural part | : 
Le constructed ot the some. time with the WASonry, Shot produc- 
2S the TAxinge 4 | 


Concrete Cannot be RE 


By. 


}3 


AS 
Gonsrete connot be tomped as firmly into a recess \Veft, or 
afterwards Cut tn BosonTYy, OS 2 Yule, os .Fo produce o perfect 
fixing, {ree from objection, Vf. the canstruction added Vorer, 
such os generalhy possrivole with. the use of OULVAINE wWaorterror. 
strond at first, Vike steel, stone or artificial stone®, | 
Bor all corbelled parts it is to be considered, that the lo- 
cations of the maximum moment and the maximum shear coincide. 
Special emphasis is to be placed on the shears; the stirrups 
and bends of the rods are to be properly distributed. For angle ! | 
beams, so iar as only an end loading: exists, the shears” are. u soe h a 
uniformly distributed as far as the support. As. ‘bearing pode. oars Gir 
are employed numerous thin rods. W1th the. arrangement (144 a). 
sufficient distributing rods “are to be provided FOr) the Slab. 
The ribs themselves might possibly be fixedto front ‘reinforced 
concrete supports. (Fis. 154). Compression. reinforcement here Re wat 
makes possible a reduction of the height for Tixing.— ee we 
a. Balconies and bay windows. ge ie i tee a 
The construction may ¢roceed as in Fig. 445, Te. a simple een te te 
ed balcony projects from the wail, so must exist. tne load nec— We 
essary for fixing with at least twofold ‘security. (aside: from es 
live load). The balustrade say likewise’ be constructed in baal 
inforcead concrete; for iron railings wooden: plugs are set an 
the -concrete © ree Dame 3 sae Aycan verticals.. | 


the beams to the oat wall \Pig. 445 " or “to” commence | oh. 
2 separate header in the flvor panel(# Fig. 445)b).. One seeks in 
such cases to make the toac on the beam supporting ‘bae- wall as 
light as possible -- by the arrengement of great window open- * 
ings and by tné use of Ligue bricks. Particularly advisable is 
reinforced concrete for bay windows not: ot rectangular plan. ae a 
(Fig. 146). Fig.147 sbows see constraction of a bay” window Lee uae 
2 commercial bulleing, whe! supporting skeleton represents se one 
stiff framework, and wacss !ront beam also has to support. the Tine Sg 
nesonry panels. (Also S@e Fig. 2960). The arrangement of a gal- 
ery on the facade of » factory is represented in Fig. 148. | 
ig. 149 gives an exaw) le for the construction of 4 loggia. 
Fig. 150 shows bow preiersble esinforced concrete is for COR 
celling out upper ste@wies on dear or rocky sites. 
b. Galleries for salilg, therches and taeatres. 
for all gallery strueture: rejeforced concrete is adapted 


253 


. 
ry I 
1 ‘ \ 


74 


ye 


AQ ah 

in the best way; security against fire ‘1s complete. Very wide 
prajections are possible; otherwise the number of vertical sup- 
ports is reduced to the least possible, which naturally aids 
in cheapening the construction. The Supports are thin and Slen- 
der, thus obstructing little the view of the visitors to the 
theatre. In all cases from every point of view in the auditor- 
ium must be a free view of tne Stage. Ceilings and walls may 
be so shaped, that at the same time -- by the construction of 
hollow spaces -- they are adapted for .purposes of heating and 
ventilation. For projections of at most 1.5. to 2 m come in au- ‘ 
estion for simpie slabs; ‘greater projections make. Bpecial sup~ 
porting beams necessary. To reduce the dead weignt is employed 
pumice concrete or hollow steps, as well as light railings as 
possible. Since the galleries as a rule descend steeply toward 
the audience room, the supported beams must generally be cue 
Cantilever beams as in Fig. 144 ¢ may then only be used, if 
the weight and thickness of the outer. walls stile the to produce 
Stability. ; . 

Some examples oi usé are shown by vias LOL GO 156. BE 35 aaa Fe A ies 
desirable to have a plane surface beneath, then Rabitz or Duro 
coverings are used asin Pig. 153, 155 .a. Notable are the rib 
consoles of the first balcony in the new City ‘Theatre. at ‘Duis-— 
burg 1 snown in the last illustration, Here are employed cast 
steel plates as slip bearings, that cause a gooG possibility | 
of expansion of the construction, and that indeed transmit: ver- 
tical loads to the supports. Fis. 155 b shows the constraction 


of a gallery tloor projecting 4 min S. aria Charen | ‘in. ee 


pach-A.¥ 2 the strong fixing in the masonry pier has phen 
suheseas here statically. The ab cl ‘is executed. ‘in ‘pumice | 
concrete. 

Note 1. PeTD. B& Be dees. ok AST. 

Note 2s. pesSe B & Be AQAA. ine eeae 

Fig. 156 exnibits a gallery structure executed by Rank bros., 
yunich, with 2.> B projection from the face of the wall. The a 
consoles are arranged at distances of to 4 m, and are connec- 
ted with a girder 04 +cm wide, that rests on the wall piers, a 
and has to bear the weight of the wall. dhe ities is tuemnen. 
for the steps is used lean concrete. 

For the supporting framewor} in ‘ae second balcony of the n 
new Peoples’ Theatre of Munich, the amderside is covered by a 


es) 


Ks 


50 
Rabitz ceiling. (Fis. 157). Aside from esthetic aims, first by 
this the acoustics of the room are improved, and secondly an 
excellent ventilation is created, the foul air being led away 
through the hollow space produced. 

Balcony structures in the New Theatre ai Frankiort-a-M. are 
represented“in Figs. 15&, 159, 160. 3 Supports are avoided tar- 
oughout, as well as visible supporting beams. The corbelled s 
slaos form a reinforced concrete bean €xtending beyond the wall 
piers, and are still further fixed to the adjacent corridor. ‘f 
floor. Also in the: balcony console illustrated in Pig. 160 and 


? corbelted out nearly 5 m. The slab must have a Gepth of 50 cm 


at the support, and be directly connected. with the. adjoining © 
masSive reinforced concrete floor over the vestibule. — Ap 
Note 3. Peld. B & Be 19412, B. eae 
On the new City Toeatre in Duisburg the rows of seats in the 


galleries are supported by a tramework in two parts (Fig. 162), a: le 
to which is connected the girder of a foyer ceiling. The frames 0" 


work itself is concealed from the visitor by @ Rabits covering. | 
Pig. 161 shows the form treatment of an auditorium truss With 


ceiling ana balustrades in reinforced concrete: the Rabitz we 


ils only serve for storing cleanings tools ang tee like. 

For the insertion of a gallery ‘In 8 pall shift framed truss- 
es serve a good purpose, if ‘one desires to avoid intermediate - 
supports. They came ‘into consideration perticulerly for, rine 
picture theatres. Beas. 

By Figs. 163 to 165 is visible the’ form treatment of a gall- 
ery addition to the Colosseum Theatre at Pforzheim. In the ex- | 


~*~ 


, isting hall was to be inserted a gallery crajecting & to om 


at tae sides and 5m at the -middle, without dividing the. inten)" 
rior by supports. A beam was possible only at one place, siven 
cy the plan of the existing enclosing walls; subordinatetbeams _ 
and consoles were not allowed. ‘The chief Support was shaped as 
a [rawe with loaded transverse member; the lower tension memb- 
er was placed under the floor of the hall. ‘This truss exerted — 
only vertical pressures at the supports; any thrust against t 
the side walls-ig thus excluded. his example shows ‘in a very 
striking manner, he ‘in general the proportions given to rein- 
torced jconcrete are flexibly adapted, and how ‘in particular, | 
it is required to furnish the only suitable building material 
for the internal supporting structure cf our theatre buildings. 


Fes 
if 


+ 106 exhibits the gallery flocr of a-moving picture thea- 
lt by the kK. Powmer Ca, Leipzig. The room has a clear & 

n of 13 w5 the gallery floor prajects 2.7 to 3.0 m and is 

x aes deca st itis A ice hae by 5 corbel ‘beams: 


er supporting the Peds eith 8 clear span of 43.0 m has a cross 
a ion of 30 x 75 om, The balustrade is likewise constructed 
Fe reinforced concrete, as well as ae projecting room means 
the gallery. | | ‘ 
- Aecording to Fis. 167, the girder supporting the eattecy may 
serve at the samé time as a balustrade, and enclose the. ealle- TS a nea 
ry next tne main hall. The omission of the post constragtion fi ee cag Sons 
educes the déad weight of the girder. a Py aes Sra ie ie 40 
A section through tne balustrade of a lie ihe floor firoly eee @ ae 
tixed wogether is shown by Fig. 168. | | a 
c. Consoles and supports for crané tracks. 

tf one employs steel beams for a crané track, gonsoles. of 5 Mane 
inforced concrete are sufficient, that are to be proverly eee 
pred to the supports or the wall. Consoles: arranged on one oe 
ore sides cause tae supports to bend, when no side Stiffen- 
by adjacent roof slabs 4c) or intermediate floors dflexieto ) he 
ntinuous support of tne ,crane rails by a continuous. peint- ee 7 
girder is shown by Fig. 169 €. Bxecuted examples of tee 
rders in reinforced concrete are evident in Figs. 169 i, ie 
lp ke Fig. 169 k represents tne form of a crane Support. ‘Ty oe 
boat storenouss; the supports here stand at distances of OF ass 
one side the support is bordered.by a straight line, on ‘Ane 
r side next the interior the shafts of the coluans are set 
ro the corbelis. -- Notable finally ‘LS also tne construction ia 
he console reproduced ‘in Fig. 409 ; for a 10 tonnes” ‘crane | 
a wall or tamped coucrete. The: consoles combine with 2 con- | a Geman Mee 
vinuous girder, tnat tends to rotate, and must receive the re- a 
au ired ‘fixing load in the most untavorable position of the cr- Late ¢ 
ane, 2 | | 

eke. L, PeSt. Arm. Be 1211. P.32D0 
‘ example of the later addition of a console to an existing 
reinforced conerete support is shown by Fig. 170. 
On other forms of corbels, seé .p. 111, 112, 219, 125. 
ae hint forms of ulate iocestoc lia ‘in beer te hae at 


Pigs tes Meee 
conte aun ; 
: FeO ea 


Fz 


52 . ses Re aaeng bse eae 

concrete, 1% must be admitted, that the unlimited freedom in é 
the Lorms given to the new building material leads to manifold 
errors and architecturel sins. Men believe themselves compell- 
ed to Conceal the supporting structural members, and produce 

wall facings of ordinary masonry and enclosed columns in wood, 
while street Tronts receiveda facings layer of terra cotta, of 
narble or the like. But men again attampt now to return to S0- 


a a ee 


undér principles, and to obtain a dignified and esthetic devel- 


opment of compound structures by omitting ail. ugly and unjust— i; 
ified concealments of the separate structural mewbers. They ive oF 
treat the conerete, especially for house facades, ain a. ‘perfect- 
ly uniform manner with wallet and chisel, as for granite and = 
sandstone. The ceilings present effective and easily ornament~ 
ea surfaces, and since the color of the concrete generally has 
an ugly-ettect, they can be painted in oil colors —: wig 
cessary -= have coverings of stucco and other materials. Also 
see Part:t. etna ane 

woat concerns the hygienic. advantages of, reintorced concrete 
for dwellings, it is to be stated, that a first occupancy ee 
re is not to be feared. Portland cement is’a silicate of ‘Line 
and reguires moisture for hardening, thus being the opposite 
of lime mortar construction, where the lime bat Slowly erreay, 
up its moisture by the breathing of the occupants, oe were 

There is further another point. of view, which places the use 
ef reinforced concrete in house architecture in a ‘specially 1 aN 
favorable light; the recognized sreat security against danger 
from lightning. The building materials themselves afford natu-_ 
ral conductors of lightning; the released electrichty is. digta. 
ributed over the entire root (s0" far as it consists of having a 
reed concrete) on a large surface, and in consequence of “the a 

reintarcement of the walls and supports, Can pass to the. earth 
in many lines. Special lightning rods and .earth connections a 
are thus not absolutely necessary. Moreover no danger to life 
exists, sincé conductors are enclosed in concrete on all sides. 
Only where no direct reinforcement with steel exists, may occ— 
ur a local destruction under some circumstances, but which will 
never aifect the strengtn of the whole. @i the roof dces not 
consist of reinforced concrete, then naturally as for all hou- 
ses, lightning rods and conductors are to be provided. + 

Speciari forns of floors and cevbings. 


“Or rooms under 3 m clear 


Kay 


D3 
gnedial forms of floors and catiinan 

For rooms under 3 m clear width as a rule are taken Fille 
floor slabs, in other cases ribbed floors. A combination of b 
poth forms of floors ‘is shown in Fig. (491. The horigontal thr- 
ust of the vatlted floor will be kept from the external wall 
by the insertion of T-beams. A construction like Fig. 172 cor- 
responds to a special desire of the architect, In Fig. 1973 is 
represented in section a semicircular reinforced concrete vault 
with cofiers on the under side, suspended from reinforced con- 
crete girders. Special arrangements to ‘receive the horizontal ~ 
tarust are thus no longer necessary. At the left of the Figure 
is represented tne construction of a window compartment. aoe S 
the ribs are not to remain visible, then Rabitz saith are. 
employed, or hollow block ceilings. (p.19). 

Some examples of the possibility of the most varied forms of 
ceilings are mentioned in Figs. 174 to 176. The bake ovensoOn — 
tne floor of a bakery shown ‘in Pig.) 175 each weigh 35 tonnes; Rae 
tney are isolated below by a cinder ‘filling 45 om thick and be Me A ae ND, 

vt layer of fireclay. 1 pig. 176 shows the form of a floor ina = ane 4 men 
dyeworks. An intermediate floor with frojecting roof ‘is. Pepre- Were GN 
sented in Pig. 246, pill. — mint Ka ; Rb ali 

Note 1+P-84. Further see Art, Be 1@11. ReBTB. as ve ee ae 

An upper ceiling of a Stairway is ‘shown by. Fig.) Meage By Fig. Orie 
178 is evident the form of a Monier ceiling suspended between | 
I-beams in the rebuidding<of the University of ‘Munich. The mid- Re yi 
dle portion ‘is coffered. Toward the enclosing walls ‘ghe ceiling 

galls about 1 m and passes into being supported by console forms. 
Deor and window lintels. Cornices. . re Pe 

Door and window openings may be covered either. by peetoreen 
concrete lintels constructed ‘in place ‘in forms, or by previous 
ly made concrete lintels. The latter have the disadvantage, t 
that they are very heavy, and therefore are set with abeioat eg: i ea 
but their widtn may be divided in several parts (180). The Pent my 

_veal of the lintel may either be formed with the first portion = Q 
in one piece, or it is formed by setting one piece corres pond- 
ingly lower, as in Fig. 180. b. The construction in reinforced 
concrete will then always be cheaper than the use of iron beams. 

bintels in reinforced concrete are then especially in place, 
when they can be constructed in connection with the floor (~ 
(Fig. 179). But also with wooden beam ceilings are frequently 


éuployed reinforced concrete 


"au 


54 
employed reinforced concrete lintels, since these form a good 
reveal for the window . The retnforced concrete lintel is fre- 
quently left visible externally, covered with stucco as on a | 
covering by masonry. 

Some examples of construction are represented ‘in Figs. (179 
to 189. Pig. 181 shows a factory-made window Sill, Fig. i162 a 
window lintel and sill made in place, which at the same time 
must Serve aS a wall beam (also see p. 90), and Pig. 163. is a 


Saxonia floor (Wolle system) with reduced Gepth next the window. 
If particularly great surfaces. are necessary for toe admiss- ee 


ion of light, then must one give the least height possible to. 
the window kintel as in Figs. 184 to 187. The lintel beam. may 
entirely disappear in tne floor. it is proper in this case to 
place the main beam at right angles to the external wall and . 
tne side beam parallel to it; thus results in this way a strong 
reauction of the weight of the lintel. Fig. 185 exnibits the 
form treatment of a prajecting main cornice. — | | | 

on teeta in richer forms are presented in Figs. 188, | 

9 (Kell & Léser, Dresden). In one case is an external facing 

of the reinforced concrete construction; ‘in the other is empl- | 
oyed projecting cencrete against a reverse plaster mould. (Fig. 
189). The parapets are here : cm thick, and are isolated oy 
an internal half brick wall.- In both cases the ‘pliers: of the 
enclosing walls are made of reinforced concrete. 

Kote ~tepe 8S. ALSO See PVG. BIB. 7 

Cornices in reinforced. concrete can be ditectly canscores we 
with the story floor or the attic floor. Otherwise they are t 
treated as simple corbel slabs (Fig. 185), which at the sane 
time nave to serve as protéetionsifor suspended mouldings, ter-_ 


re cotta and the like. By the use of facing concrete and ooff= 9. 


ering tae under surface may be produced beautiful erchitectur- x 
al effects. An example of such construction is snown by Fige 
i190. The floor of this story and window lintel lie below the . 
cornice slab; they are connected together by 2 continuous: rei- 
nforced concrete wall at the inside of the wall. 
Chimney flues in reinforced party walls and openings in 

flcers. 

Vasonry Chimney flues as a rule must have & thickness of at 
least 25 cm at all sides. For the construction of party walls 
in concrete or reinforced concrete (for solution with reinfor- 


ced conc rete pier 


es 


reinforcea concrete piers and beams with masonry panels, seo 
pe 89), the Berlin building officials made the following bares eh 
(Regulation of Haren 19, 1913). 

“ fs The structural parts of concrete or reinforced | concrete | 
next adjacent to the party wall are to have 25 cm thickness. r) ! 
equal to a wall 25 cm thick, if the steel reinforcement is pro- i 
tected against injurious effects of fire. ‘eases at all places de 
by a concrete iy aia oF at pi | 4 Cle a ae eee 


height is not permissible, Since on account of re ee , 
long vertical butt joints may easily occur.a: ‘separation of the Ge Oy iran 
cnimney flue from the party wall, ‘particularly of the presence ie ae 
of tne hot fire gases. . DRT? 5 Ue as 
a bs this reason and to ihiety such conceivable Joints, nost 


imney flue must be constructed of conerete, ee 491. ae : 
The abutting of the ebimney flue against : a peek 


well closed by cement moran: (ie 191. ae we 

Tne supports of reinforced concrete floors at chimn mney t ucs- 
are to be so constructed, that the walls of the. chimney flues 
are not meagan i tf no Cornel aa of the Benen ye en he 


espeuie aes paudancain to the chimney aoc: ped Monier ae 
suffices a header arrangement of tae reinforcement ; as ‘in co 


193. 
NOtS Lepo8B. See the decree of the , novice president of | Bert- Ray 
W eeloting to. this. B & B. 1942. pe R20. 4 ah pea a Nae 
inat-is said also applies to all openings in floors; for la- ¢ aa is 
ree stairway openings, light or elevator shafts, the sides of 
openings are to be bordered by a steel or a reinforced frame. 
Bxpansion joints. . 

NOLS? {epe3Be. ALSO See Port 1. ph Ue a 
ixpansion joints serve to lags injury trom ‘teuperature 5 eats Shay 8 


KOK 


joint is filled with putty. 


50 

Changes, irregular settlement of the foundations, andttne exp-_ 
ansion of the concrete by subordinate stresses ‘in setting, th- 
at may easily lead to the formation of cracks. Movement joints 
are also advantageous during the progress of construction. 

The .purpose can be attained in different ways. Some possible 
constructions are shown in Fig. 154. aa 

ae Division of the girder and of the entire support down to 
the foundations. 

db. Division of girder alone; bearing on iron plate. 

CG. Free end bearing of the slab at one Side. | pi Me 

d. Free end bearins of the f-bean at one side, a ‘peetese: ribs? 
bing of the :joint suffices; otnerwise as taken an | intermediate 
thickness of metal or pasteboard. 

e. The movement is so arranged instead of the mode a, that 
the vault edge of the floor remains symmetrical abo both sides | 
of the axis of the support. 

f. Projecting cap with inserted baaee igs. see: Hig. 195). ee 

és Construction as for agptne support, has an Acted er a AS 


Joint covered by sheet zinc, that. can move freely; no gee 


oa of the linoleum cemented on it should OCCUL. — Done i 
k. Expansion joints after the mode of the Gerber beam; the 


Wall framework in reinforced concrete. filled. with aasonny. 

In great part the external walls are built of ordinary. gamely aM 
ry, only the floors, girders, supports, roofs and - stairways ee | 
(also the foundations in a given case) are constructed. of rei 
forced concrete. (Also see Fig. 209). But the external nalls 
must be very strongly constructed, and therefore also. properly oh 
bonded. If one desires to save materials in the erection ‘of t yeu Ry A 
the external walls, then he creates stiff frames by means of 6 
piers and beams, which ten are filled with brick or pumice s eee a aa ee 
stone masonry at most i brick thick, or with. factory-made cen- 
ent slabs. Likewise are employed brick walls, that afford a 
pretty architectural effect by their dark red to the gray con- 
crete. If air spaces are required, they ‘may be used hollow bl- 
ocks set vertically in two courses (see p. 58). The advantage 
of such a system of construction (besides. a considerable saving) 
of materials) also consists in this, that one first entirely ; 
completes the structural skeleton and the roof, and only after 


2 workins floor 


4f 


viness room lie in the lower story and. are Connected with the. ee ye a 


57 
a working floor is created, then begins the filling of the: pan 
éls. The walls will hold nails. Furthermore, since masonry ne- 
rely serves as a filling, eter “openings of any desired. size 
can be provided. 

An example of this system of construction -is ifocued be the 
office building of the Wayss & Freytag Co at Neustadt on. Haardt. 
(Fig. 196). The construction of 2 wali beam -is Shown by Fig. 

197 a. According to F Pigs. 197 b, a Side beam is suspended fron oe bs 
the wall beam of the facade wall, Had Lana eed ae | Ph Me i 

Tne transition to | purely ‘industrial | struetapes is. formed by aN ha | 
such nouses -- as ‘in the ‘great Cities is quite frequently SERN lO et ie 
casé -- which contain both Living. and business rooms. The bus- BO eee 


street by the largest. openings possible, | They ere separated Cae 
from the upper hiving rooms by fireproof ; ‘reinforced concrete Bie ean ak 
floors. ‘The external walls, also peaaear ly the division walls He ne 
are omitted in the lower story as far as possible and. BRE Des hy Ge ae 
olved into piers. Qne has to ado with a fixed substructure con— 4 mae ; 
Sistins of eeinforced PopCenPes which: has te Be ei the dwel- any Nias 
ling proper. ao | | Maa eeh 
Fastening transmission and Lignting Hes, | 
ihé most extensive employment of the new system of . construct- 
ion has been found in the design of factories, commerciel amd. 
other ‘industrial buildings. Here? in ‘the first place is” Tequired 
cgood use of the interior and good light ‘in the room. The great Es 1 
er the vibgations by the use of machines, the more advantageous, ‘heh Bec 
it is to employ many girders and also slabs of small span. fr-. be ian Meo ae 
eansmission lines may be. ‘conveniently fastened to the supports _ : 
and girders. Suspended bearings are ‘to ‘bee fized to the ceiling mee 
(Fig. 198), bracket - bearings to the supports (Fig. 199). a heat e | 
aring fixed to a suspended column is shown by Fig. 200. It ES BU eae ac 
advisable ‘in each case to s@ select the mode of fastening, erin ae 
in arranging the transmission line a shight. adjustment of the : 
aring -is still always possible. Already in the tamping?mast 
pieces of cast iron) ‘pipe be set in the beam tor fastening tne 
bolts of the cross pieces. | 
pee lines are to be placed on the ceiling panel and paral- 
tel to the ceiling rods if possible, not perpendicular to then. 
The wooden blocks necessary for fastening them are to be laid 
on the finished centering. Another mode of fastening themvis . 


i ha 
Py | 


a2 _ 
ait 
einen 


shown ‘in Fig. 201. 
fhe planning of transmission and lighting lines must be done 
in all cases early enough to avoid a later setting of dowells 
and of iron, which is always costly. L 
Note inpsSB- ALSO Bee B&R Be 1810. p.202. 
The construction of platforms in general proceeds according 
to the same principles, as are given on p. 7i (Figs. 144 to 150). 
figs 202 snows the substructure of & warehouse founded on piles. 
AS a termination next the handing ‘side, if no cellar. be TEequde 3h 
ed, may also be assumed a eeinforced concrete bearing wall as’ Kae 
in Fig, 202 b. According &o Figs. 203, 204), special creme Ce 
for the ramp are omitted; Fig. 204 shows a construction where. , 
“4 tne edge beam of the platform is. supported by obtigue struts s 
/~ set on) the foundations of the wall piers. Ho protect the - ‘edge 
of the platiorm slab as a eee Serve steel ee Wak ‘channels: - 
(Fig. 205) or angles. | oy 
Driveways and bridges over streets. PGR Gh ie ae Si Mp 
4 gimple example of a bridge over a street’ is shown in n Fig. 
206, an example of a dreveway: between streets in Fig. ‘2076 a, 
in the last case the pridge serves to receive & two-story con 
ecting building. The span amounts to 13.0 m, the width being | v3 
10.35 me It would have been better statically to have employed wae 
,, tivi lintels as in Fig. 207 Lk; but certainly for ercbitectural 
14 reasons, only three kintels are used, tae floor being. made de~ 
eper at the corresponding places, in order to produce 1 the nec- i 
essary compression zone for the lintels. i. patie | ki 
Kote Aopo8B. Ano vridges over Streets, OVSO See Kereten?s Mad 
Brvages in reinforced concrete, dist Too3 TO edvtion. Ie Roofs 
28 brvage passages. i 
Note 120-94. Burther see B & Be AVLA. 06128. 
Fig. 208 represents the section of a rebuilt new. factory Bal 
Th. Lehmann Ca, Halle, and Fig. 209 is the section of a eats 
of Industry of A. Vetterlein & Ca, Leipzig. The roof of the 
_ structure last mentioned is builtin wooden ‘construction. The. 
fi live load on the floors was fixed at 1000 kil/n¢, that of the 
ceiling of the cellar story being Roe kil/ne. The’: floors and 
beams are mixed in proportions of 1: 2.5 #225, the columns 
being 1°: 1.4 2 (1e5;%,0n sho eeaauiduhs eee Bbra) 
ess of 45 kil/em. Further see B & B 1911. p. 381. | he 
Floors for commercial and industrial rooms. 


aie 


On the covering of intermediate floors, see p. 3. 


96 


“setonmurelineum”. 1 Tt not only prevents the formation of 


ey, s Fea acl 
Floors for factory rooms first of all must be resistant to ee 
mechanical wear (walking ‘in textile factories) and against the =~ 
formation of dust produced thereby. bikewise they must resist 9) a 
acids, oils, fecal matters and the like. To make them as water- 
tight as possible, the Nae igsin er" hair cracks must ee preven- 
ted. ; La Mea 
For rooms without cellars beneath them under certain. condita 
ions suffices @ coatings 1.to Z cm thick of strong cement re Fig fe 
to 1:3 on a corresponding basis of reinforced concrete, or. A SAN 
a layer 10 to 20 cm thick of tamped concrete, 1 oa: 68 to. an Ae aes ii 
foo rich a coating (for example 1: 1) not. only produces neon oe te 
aust but also results more quickly in the. formation of ongelis ec Dh 
As a means of hardening. ‘is frequently added iron filings. B. Bes 
But mesallic iron is already attacked ‘by very wiak. reagents: Rae 
in damp air and pure water the iron is: quickly changed intone 15 Gs 
powaered iron rust, that injures the concrete. Better LS an ad- 
dition of iron oxide polish, or oxydized ge that resists a ” 
all chemical reagents, is free fron grease, s mixed finely | 
SROnAT bahar, to the surface ‘the shine ot dencine sandston 


He Cohn, Berlin - Neuk0lin, ‘in autierent tints and varies: ‘in 
neneSSe es Sane Se ee 


conerete to secbanical: wear, ae Broese @. ee. 
Hriedenau, has introdueed in the trade ‘the coating 2 


ite ey 


st, but also of injurious effects: of the fatty acids contained 
in machine oils. The material mentioned forms: with the concret 
a chemical, mechanical and inseparable combination, incre asin 
bath the resistance to water and also the crushing strength 
tne concrete. Likewise the formation of heir cracks is. ‘restric- 
ted. The concrete ‘is then proferly to be coated first with the a 
murolineum, when it ‘is three or four weeks old. An addition of 
the material in making the concrete must not be made. ) 
Note ~1.p.9d- AL the AInstance of the firn nentvoned, | expertm- ea Maa 
ents mere wade WH the Royo Morterrvarls Destine. “Lovoratory ot G. 6 3 
Gross- Lichter felae.e. They showed that concrete blocks of the 
Some noture Lost under a sand blast of 3 otmospheres pressure 
S807 Grommes WIThOVs coating and only 33,0 after coating, 
For schools, hospitals and commercial rooms come into consid- 


eration other requirements | : mr ae A Sieh \ 


ay 
K 


Aina 


2 
noe) 


60 


come into consideration (resistance to mechanical and chemical 
influences), which demand the use of special coverings, These 
coverings must be fireprool and resisi fungus, obstruct sound 
and be warm to the feet; they must be elastic under the feet, 
and make sate walking possible, as well as gens and thorough 
cleaning. 

Stoneware slabs are cold to the feet, and on account of the- 
ir smoothness cannot often be considered. 

Stonewood, a applied as a paste on the concrete, ‘is draduet 
tly employed, but requieges a certain tine to Orme and y aiateta 
Skill in the workmen applying it. . eer ye wot La 

Note 167.86. Stone-wood ahiveft iy congists. OF 0 wren percentoge ie ; Oe ae 
Bf Wognesite, o cementing moterial, oa permanent acid color, ae co p 
And .o Corresponding choice of 6 AVWVind ROLerVar (sondust, pe 


OUNnd guortz, eboss SOR, cork mer, Bi heap came, ward, a a 
the Vike). a | ; oe De Oe CRA ae 

if a working Woot to be used. at once ‘ie desired, ‘then » ESO) ve Hea 
preferably used stone-wood in the form of tiles made in ‘factor: 0 
ries under high hydraulic pressure, the so-called sxylolith OS Ne a 


es of the eat Rhee i ptiedaace ‘in ee eae near ore 


is almost exclusively 12 to 14 mn, for ieeags of steirs. 20 to. 
26 mm (See p. 63). As a rule the tiles are 20 x 20 or 25 x 25 Bate 
CM in Sige, and they are set on concrete with ‘magnesia mortar. i eo 
ai for large surfaces are usedwwood Strips saturated with care 
bolineéum and set ‘in the concrete, then the tiles may assume ao 
dimensions of 10 x 100 cm. 
G. Roofs and Hall Buildings. 

Roofs of reinforced concrete afford the advantage of greater 
resistance to fire. As well known, the fire officials permit 
no wooden roofs for movering uorking rooms. Furthermore, wood 
has little resistance and by insects and fungus may suffer rap- 
id and unsuspected deéstriction, Bkisting wooden roof framework 
can be made safe-in fires by Rabit® or yonier coverings applied 
later, or by @ corresponding treatment of the attic floor. May 
be separated from the dwelling (For example Pigs. 177, 175). 


18 


61 

vor roofs of steel, the same is true as for stairs of steel; 
the rea hot members bend, break up the attic floor and destroy 
whatever 1s beneath. If the cost of construction of a roof st- 
ructure in reinforced concrete be greater than for a wooden 
root, then the economical advantages are more striking, parti- 
cularly for industrial buildings. In reinforced concrete may 

be constructed wide and airy attics with fey or no supports, 
ties and struts. The under side of the concrete covering: may | 
be treated in the same manner as for ceilings. it can be cover~ 
ed with gypsum, coated with fluates, and then ornamented by ip” 


painting, etc. If one desires to prevent the ‘injurious ‘influen-— neal 
ces of the external temperature, then is. ‘recommended the arran= ay 


gement of ‘isolating air cavities. pers doy als, aay 20»: as. 
wel}iag ips 100 janie. | . ee arg mae ae EON ar ke 
“1. Root coverings and means: laf is tation: ae Baca 


The covering of a root Pequires: varbicnlar attention. affects 
of weather and constant ‘variation ‘of. ‘temperature: erack the’ ‘con- 


crete, and the use or attics as ‘Diving and: working Toons, Ee bi. 
not .quite ‘impossible, is still ‘inconvenient in a ‘high: degree. 


The roots afford no. proteetion. from Tainwater. Neterproof maak 


aps 


ings are generally not. much | used, “since hair cracks are soon 
produced. Likewise coating with var, asphalt and combinations — 
ot these do not make: the concrete. permanently tight. ‘One ‘isc 


compelled to use special bituminous coverings, Mite he does. not 
wish to resort to the otherwise aged Kinds of coverings (slate, 


metal, tiles, ¢tc.). eile ae ri at | ASLO eA ie ME USB HEN ve 


A good ana usable covering aabeepah has to. satiety many’ Noone 2 
agitions; it must not crack, does not. drip, without odor ° rut ROSs 


sible, secure against weather, storms and hail, flexible (not 
stitf and brittle) and -- be cheap, It must also be safe from. 


soot, be easily. Laid, must remain smooth and without folds (ey- 


en under great radiation from the Sun), Hust not .dry rot,' mast 


latetiredubrethittle or nO painting, which makes ‘much ‘cost, es- 


vecially for StEED roofs. It. must. be adapted the most possible 
for all climatesand zones, as well as for all ‘inclinations of | 
tne root surfacessThe cementing material must not be melted 
by thé ‘internal. warmth of the pduilding; likewise must occur no 
gradual loss of tae. ‘saturating material. -The condition for a 
£00d permanent date dion of every covering is a dry, smooth and 
plane upper surface of the concrete: there suffices a simple 
striking with the straight edge. ' | 


~~ anceps: 


yea 
Minera! 


62 

If one employs simple paperboard coverings, then must one t 
take care, that the board has sufficient thickness. A saturat- 
ion with coal tar (and its products) ‘is not generally recommen- 
déd, since coal tar escapes too quickly and also stinks. The 
gradual decomposition of the saturabing material results in ‘i. 
its being washed off, that requires occasional applications. 
If these are applied to thickly, under some ‘conditions of great RO ON 
heat, they flow away and injure the rain leaders, § — Sh a ee Pe 

But more preferable though not:resisting heat is the use of == =» is 
a doubled asphalt paper or asphalt felt covering, but which eat 
can only come ‘in consideration for flat roofs, and it meee Bene TN aa: 
coated anew with tar about €aca two earses ene aie te ie 

An excellent protection from heat is afforded by a wood-com- 
ent covering. The chief part consists of three layers OF i paper, i 
bi ere Saati in a flexible watenproo? ee this 


180 kil/m?) and the net: that it can re 
ion for row BEY betes 


proved to be the rihepedd of the Buberaid ie  hoatata oe 
kind of covering has already come ‘into most extensive use, § 
nce the cost of maintenance during the first ten years” 18) 
good as nothing. Ruberoid is a tough leathery woolen felt, s 
urated by a waterproof and water-resisting Liouvid ° (“puberoia”} 
On both sides is applied a coating of the same composition, | 
but in a harder form. Ruberoid ‘is cemented on the dry concrete 
by means of hot fluid piteh. 1 ithe cement uniformly remains eo 
tough and elastic. The different strips overlap 5 to 10 cm abet) Pe Wan 
the eGges- Ruberoid coverings remain entirely smooth and flat = 
and are suited for any inclination of the roof. ‘They ‘mostly She oe 
have a dull gray color, but may be painted red, green and oth- ae 
er colorse Ba ict an on 

Note LePeWSe PLEGH “AS Kade from Trinidad asphalt vy wixing 
with 2d per cent of the residues {vom distillotion of petroleum. 
It Vs not to be confused with resin, the vesidue fron distilled — 
tor from wood. 


Purther, especialy for mansard roofs, a slate Ot 


ee 

int 4 

Speen shi eee 
5M BR Ys age 
ny i 


[oo 


(Of 


63 
Further, especially for mansard roofs, a slate covering may 
ve employed. This can either be nailed on wooden sheathing Tas- 
tened to wooden strips set in the concrete, be fastened to ir- 

on bars, or directly on the concrete (pumice concrete). Metal 
laid directly on the concrete without an intervening covering. 
is unsvited as a coverings material, since it conducts heat too 
well, thus producing injurious stresses in the concrete, made. 
apparent by the appearance of cracks. In ail cases is further 
advisable a copper coverings on domes, churches and tombs. She- 
et ginc is not to be employed without wooden sheathing or a ie 
layer of pasteboara, since it is rapidly corroded by rich con- 
crete. Finally also tile coverings come in consideration, for 
reinforced concrete roofs, indeed for an ‘inclination of the 
roof equal or greater than 35°. | 
Freouently exists a need for a special Sasulanion. A very. 
good insulating material ‘is a layer of cork 3 to 4 ch thick, 
laid directly on the Baa and covered watertight with bil-: 
es or roofing feit. + Likewise a protection from neat is also 
as a good material, a © to & cm layer of cinder or .pumice con— 
crete, than can be nailed into during the first month, for -pre- 
venting the dripping of the condensed water during the cold of 
winter, caused by warming the attic. For the purpose of avoid-_ 


ing all formation of drops is then recommenced the making of 


holes directly below the surface of the roof in order to make. 
renewal of air: possible. + | | 

Note 1.p-100. A&A separate cork GeALAng suspended Bron. the are 
ane of the roof Vs deor and nos LITtLe VELOX, - Thougn : OVSOtANG 


OW DASULATINSE HOLLOW SPAGe.s 


Note BeHei0- On, the use of pumice cancrete COVVINgs, B22 Yo 
43, an suspended Rabvtz or Duro GOVWANES, S22 De 103. 

‘Ppe arrangements Tor removing water from concrete roots pre- 
sent nothing new. fhe gutters are also sometimes constructed 
of reinforced concrete (Fig. 275). As shown ‘in Figs. 210, 211, 
the suspended gutters may be omitted, if by a corresponding e 
execution of the concrete, the water is conducted to the aiff- 


erent leaderse 


2. Roof surface on steel framework. 
Figs. 2i2 to 215 show different -possible ways ae constructing 
reinforced concrete surfaces of steel ‘root trusses. 1 such sur- 
faces are nearly 5 cm thick and are constructed on wooden cen- 


64 

centering in the same manner as plane :floors. Arched ends as 
in Fig. 212 are less advisable; it is better to insert intern- 
caiate purlins, thus subdividing the dastance a between purl- 
‘nS. Stronger prinpicals are necessaazy, but the required thick- 
ness of the slab is so much less (as a rule 5 om). For larger 
Surtaces is recommended the arrangement of expansion ‘Joints ‘1 
cm thick, placed at distances of about § to 10 m and filled w 
With asphalt. Also see B & KE. 1907. p.176. 

Note 1.peiGi. Soe Kersten. Btee\ Bullaingso po. ANT. 1913. 

Factory-made slabs can also be used, extending from ‘purlin |. 
to purlin, making centering . unnecessary, and allowing the work — 
of covering to be done at any time of the year. Recently have 
béen employed coffered slabs of pumice concrete, Tastened by. Z ‘e 
nook bolts. Pigs. 216, 217, exnibit examples of the construct- 
icns of the Bridge-building Co. in Neuwlec-o-Rh. A pumice con- 
crete covering built in place (by R. Grashof Co, Hanover) tor 
the Locomotive Repair Shap at Stendal is evident in Fig. 218; 
a shows the section through the roof slab, bis the section t : 

through the skylight beam, c and d are sections through et € e 
edges of the skylight. : 

Pumice concrete is very much used, particularly ‘in ) manutact- 
uring regions; it is very light, insuletes from heat, and is _ 


tregquently cheaper than gravel concrete. ‘The lower visible sure 
face is properly coated with milk of cement and is then Banat hae 


ed with lime colors. The upper surface is covered by Tuberoid 
or an equally scod bituminous material. | the Joints: and expan- 
sion joints are covered by sheet metal, (Zinc, no. 14, to: fo) ey 
ror a mixture of 1 cement +3 pumice sand +- 3 quartz Sand, one — 
may count on &@ maximum :resistance to compression or ebout 140 Dek 
kil fem. , hy ee ea ‘ 

Note 1.p.102. Pumice concrete is .porous and thus absorbs wa- 
ter. The covering of roof surfaces must therefore ano occur 
when the concrete Vs perfecthy ary, otherwise it 1s to be fear- 
2d. that the cenent of. the coverine wild be arissolved., 

Further see De. 43; as well as Part I. 

Tf an air space exists between the profer roof me ar and 
the Monier ceiling, then may it be designed according to Figs. 
215, 220. ‘The ceiling slabs are then cast between the purlins 
as for floors, or they awe factory-made pieces set between tO 
ars, that extend between the principals. Finally also a Rabi- 


tz covering suffices for wooden purlins. 
4 


ci 


Soy 
eins 


/o4 


06” 


65 

if the steel trusses are to be ‘protected against fire, then 
& bignt Rabitz ceiling may be suspended from the lower chords, 
which as seen from the interior phoduces the appearance of an 
arched roof.(Fig. 221), 

- Beam roofs. | 
ae roots in reinforced concrete are generally to be design- 
€a accordins to the Same rules as beam floors described on De 
32 (with smaller live loads). This ‘is especially true of flat 
roots, tnat very frequently come in vacated aaah fpr Tor industr-— 
lal plans. | 1 By Dee a 
for the calculation as a rule the following hice loads are 
determinative. iy | a 

1. For an inclination of. 0° to -15° tie oat suriace is breat—_ 
6d as a horizontal Slab and Rie pag for a live load of toy : 
to 300 kil/s, 

é- #or an inclination of 15° to 60° is assumed a Revaion 1 
load of 150 to 200 kil/a* for snow ioad and wind pressure. 

3. For an inclination over 60°, one only needs to take the 
wind pressure of i100 iil /n* into the calculation, since the 1. 
lying of the snow on the roof is excluded, . | 

The danger, that on account of temperature chances cracks » 
may form-in the concrete, naturally €xists in roof surfaces in 
a higner degree than in intermediate floors. Tf no. ‘insulating 
material (p. 90) is used to a sufficient extent, then €xpansi- 
on joints are to be placed at distances of 20 to :30 a, indeed . 
lengthwise as well as crosswise the axis of the structure. The 
joints are closed either by filling with an elastic material, | 
or by suitable arrangementr in the coverings of the roof. The 
division joints can only extend through the slab (Pigs -222), 
better is a continuous division through beams and Supports, 
(Fig. 222 a), or only tnrough a beam (Pig, 222 b). Slip :joints 
as in Fig. 222.e are generally less advisable. Foundations are 
not to be divided so. | k For lighted sheds, the Skylights can 
oe Separated according to Pig. 291. 

Note 1Lep.i04. ALso see what Vs said.on p. 88. 

The flat roof of a high reservoir building hear Metz, repre- 
Sented in Fig. 223, Is covered by wood=cément. Bistance between 
girders is 5.6 m, clear span ‘is 16.8 m. Even the roof house is 
constructed in reinforced concrete. 

Fig. 224 shows a roof of a moving pictura hall with vaulted 


( 


66 


{07 


66 | : 
ceiling. dhe use of stiff frames here must be rejected in des-~ 
igning on account of too thin external walls as well as the c. 
construction of a vault. 

Fig. 225 gives an example of a roof beam firmly connected w 
with the wall. Naturally here canoot be a statically Tixea end 
free from objections -- on account of too smail a live load. 
Fig. 226 exhibits the form of a projection of the root. 


Hig. 227 shows the use of Visintini girders, meade in a yvact—_ 


ons and set in place in complete condition. (See De 30). 


4 gable roof (roof truss over tne transport snéa of a Eger} 


nouse design) is represented «in Fig. nay © 
Pyranidal roofs. 
Figs. 229, 230 exhibit the construction ‘ot a pyramidal roof 
of the water reservoir represented in Fig. 47. The Poot is ‘i 
S om thick, buibt without ‘ribs and strongly strengthened at: t 


the apex and the lower support. The roof is covere d with tiles; 
it is covered with 3 cm of pumice conorete on wich are bearers an 


nae the tiles;(beavertail). Lee | 
A pyramidal roof With projecting roof slab-is shown in Figs. 
oe 232. Another quite notable construction of an automobile 


garage with a:roof inclined on all four sides is shown in Fie 
233. The bottom beams (foot purtins) salons the wea its are: regar- 


dea as tension ‘connections and rest on supports, let ‘inte the’ 


walls. Middle supports -are not ‘provided, in spite of the cons- 


iderable dimensions of the interior (20.74 x 16.18 m)+ yet the 


root surtaces exert no thrust. At the middle of the root is. a Me 


arranged a glazed lantern 5.3 -x 6.1 2). | : 
Factory roofs. aN 
Factory roots are merely a special form of the bean root's Dd 


previously mentioned, that come into consideration tor textile 


factories in particular. }Weaving sheds). On account of their 
great horizontal extent, they require admission of ligkht over— 
nead. A distinction is made between monitor and sawtooth roois* 
Sawtooth roofs are generally not so much to te recommended . 
as monitor roofs, which are flat roofs with skylights placed 
on them, that have a betterilignting eifect and in their loca- 
tion are independent of the orientation ci the building. The 
removal of water is Simple. The skylights are placed on reinf- 
orced beams about 30 cm deep, and best with stesl frames, that 
are fastened on the ‘concrete . Under the skylight is omitted 


wane root slab, : | 


apts 


2 


HVA. } 
ret Auer a 
gabe 


67 


/o¥ the roof slab, so that there the T-beam extends :free as &@ sin-_ 


ple rectangular beam. AS a:rule itis edvisable to ‘inerease t 
the aepto of the beam at these places as in Bis. 234. As in FB 
Fig. 236 a lignt Rabitgz ceiling is supported from the roof bte- 
an, at tae light openings are provided glazed ceilings. + 

Nove LepeiO0S. Hith o simple skyliant o considerable formati- 
On Of Grip Wou occur An winter. The second eé\azed covering bert- 
ter equabizes the difference of tewpercture, though reducing 


the odmissrian of Light. 


further notable examples are presented by Figs. 237 to 240. 


[0 ii An automobile garage in Vienna (Pig. 241) is combined of st. | 


//0 


iff frames pivoted at bottom. (See pelle). Distance between ft 
frames 5.1U m The roofing slabs have no ribs and nave light 
openings 1.7 x 7.3 m, that lie between the frames. Further see 
Arn. 5B. -1913.p.8. | 

For sawtooth’ roots, the glass surfaces must be towards the 
north; their construction is somewhat more aifficult than that 
oi the flat monitor roofs just described. A Structure corresp- 
onding to steel construction is shown by Fig. 242. According 
to Fig. 243, the massive tension beams a are replaced by free S 
Steel tie-rods; distance between trusses 8.8 m 1 in this way. 
1s produced & light appearing construction castings little saad- 
ow. Still more advantageous -is it ‘in this respect to also omit 
the steel tension rods and to construct it as in Fig. 244 with 
Stiii frames and with bent up chord. More simply formed ‘te 
construction with vertical skylight as ‘in Pig. (245. ie Bet 
notable are tne modes of construction shown in Figs. 246, 209° 
Particularly the form of roof shown in the last ‘illustration | 
but with two glass surfaces on each panel between columns ( 
(invention of Dr. Bauer) may afford certain advantages for cer- 
tain textile works. 

Note -L.-p-LOS-Burther see Arm. B. 1942. pH. 60. 

Projecting roofs. 

projecting roofs in reinforced concrete are architectural m 
members corbelled out at one side and as such are to be treat- 
ed according to the remarks on p. 7/0. tiost advantageous is it, 
if the corbelled prajection represents the extension of a flo- 
or. How tne reinforcement is to be arranged “in such cases is 
Tully shown by Figs. 243, 249. At a bakery in Bieleteld (Arm. 
5. 1911, p. 277), the projecting roof is covered -by glass as 


in Fig. 250. Here also the corbel beams fory the.¢ 


Ne 


aren 
ic nd 
i a 


a 


>a 


¢ 68 : 

in Fig. 250. Here also the corbel beams form the continuations 
or the floor beams. A projecting roof like a console connected 
witn the bruss posts is evident in Fig. 251.(Preight shed on 
Dertmund Railway). ihe distance between frames here amounts to 

4.5 mw, the span of the Supporting ribs being 10 m. The prajec- 
tion of the covering roof ‘is 3$16n. and is the same at beth FS 
sides. 

Qn other corbeiled forms in the construction of roof of rein- 
forced Concrete, see Figs. 238, 279 to 252, 294%, 300. 

‘Trussed Roofs. : 

Root trusses so far have only deen erected exceptionally. 7 
{ney come into consideration only for great spans and under o 
ordinary conditions require considerable cost for construction, 
which mostly sets aside the economical advantages of the saving 
in building materials. ixamples of trussed structures are snown 
in Figs. 252 to 255. Por the truss shown in Wig. 254 is arran- 
ged) a 2 horizontal ceiling between the lower chord bo ae ae t 

the deposit of dust on the lower truss menbers. + 

Note 1.9-4112. AVSO see Arm. Be. 1912. ~. AB. 

Mansard Roofs. : hea i oe | 

In statical respects one here has to de Bostly with frames a 
connected on ‘all sides (Fig. 263)or with arched frames with ob | 
norizontal thrust neutrailized (Fig. 260), If the interior be. 


divided by a norizontal intermediate floor as ‘in. Pig. 2 256, oe 


en oné speaks of 4 mansard roof in several stories, otherwise 
of one in a single story. In Svery case only vertical forces | 
are transferred to the walls. An example of this kind is evic- 
ent in Fis. 256. In spite of a span of ar? m po supports are CaN 

rranged. oa OR Ua ane 

A dormer window can be constructed: ‘in reinforce ea concrete as 
iW Figee257s A EE SO 

fig. 258 exhibits the supporting of the recessed attic of .a 
warehouse on the ceiling of the upper story bencath it. On ac- 
count of building reSulations concerning the height of buildi- 
ngs, it was necessary here to set the upper part of the street 
front back from the butlding line. 

tne symmetrical treatment of a mansard roof constructed cy 
Kell & L&ser Co, Leipzig, is shown in Fig. 259. (Trapezoidal 
roof with wooden trusses above it). Distance between trusses 
amounts to 3.9 Me. 

The arched ribs of tne mansard roof of 


a 


a 5 > A 
FaCtory have a 


\ { 
t \ 
t \ 
| 
: t 


[lf 


/15- 


OF 

‘tne arched ribs ot the mansard roof of a factory have a par- 
abolic form, as snown by pig. 260. The rics were calculated as 
elastic arches without hinges, have a unitorm section for the- 
ir entire length and doubled reintorcement. Special tie-rods 
to receive thé horizontal thrust are not required, if tne rods 
of the ribs are properly connected witn those of the beams of 
tne fourth story lying beneath them. The excess in steel saci- 
ion of the floor ribs then receives the horizontel thrust. -Tn- 
us Only vertical forces are here transferred to the walls. ; 

Hor the rool truss represented in Fig. 261, the middle port- 
1on 18 composed of a stiff framework, adjoined at each side by 
curved ceams (on three supports). Distance between trusses 3.9m. 

According to Fig. 26Ztwo frame trusses, separated by lead s 
Sheets, are set over Gach other. Tne tension member of the uc- 
per frame is placed ‘in tne beam of the lower frame, while the 
tension member or tnel lower frame coincides witha the floor of 
the attic. ey 

Iz for architectural reasons one is compelled tc use a sharp 
root, frequently advisable -- on account of economy -- is as 
superstructure of wood. It is further light and loads the rein- 
forced supports in only a small measure. According to Fig. 263, 
the roof is cemposed of Series of stifi frames, with the on- 
ission of a- reinforced concrete roof connecting the frames. T 


Ca 


oY 


The lower chord may eae oe the attic floor, or also as t 


the illustration shows, ote treated AS 18 simple attic ceiling.+ 

Note -Aspetio. See Deurts. Bouz, LOEL. ‘Boment Supplement. vo. 153. 

Another example gppears in Fig. 264, a section of half the 
third story and of the attic story of the new main Custom House » 
in Wurzburg. On tne level of the ceiling of the story is cons- 
tructed a terrace. | “Ts agg 

Fig. 266 shows anotner possible mode of connecting the wood- 
en surface of thé roof with the reinforced concrete frames. 

Finally, attention must ce paid to the construction of mans- 
ard roots with suspended attic floor. Fig. 267 gives an example 
of that. The story beneath is free from supports; besides the 
rloor is also the tension member of the frame and has no sreat 
neight of beam. 

4. Halls with frame Beams and Arches. 

Stiff frames are supports composed of straight or curved tr- 
ansverse beams (and struts) ,which in conseauence of rigid arch— 
ea connections 


mls 
a 


70 | . 
arched connections forms a united whole in statical respects, 
1naépendenat of the walls, and also capable of tra rsterring #i- 
nd pressures. Fig. 268 shows some of the rest ‘important basal 
torms. 
1. Frames with single pier fixed at base. 
2. Frames wito two piers hinged at base. 5 
Cross beams parabolic (b), straight (c), simbly broken (a), 
twice broken (e), triangular frames (f), trapezoidal trames (gs). 
with projecting cantilevers (h). 
3. Prames with several piers (hinged at base). 
Gasal form d with a hanging pier (i); basal form c with 
two nanging piers (k); basal form b With two piers hinged Bt eng vith 
pottom (1). ! aaa Oe Sa POR ss 
Tne posts receive not only gyiais forces but als dehendine Dette Baath EY 
ments, and must then have greater dimensions than for ‘freely Pa Per ery 
supported beams. (Fig. 269). Fig. 270. exnibits the moment areas a eh ee 
tor unitormly distributed and for wind. loads, indeed fOr a ie- ig eevee 
ame hinged at bottom. The changed forms anc moment areas ‘of Cie ree Me 
framé with Tixea piers are to be seen Min Pie CR ee ee mes 
Hinges at the bottom are Ssenerally the rule. The: side. forces Ni BOE anes 
occurring ‘in each case are taken by the foundations. ‘Otherwise ‘A 
(for example with defective foundations) tension members are a Rea UN 38 
to be provided as in Fig. 276, which nostly lie below ‘the flere ap Ores 
or. On the treatment of the foot ninges, see p. 51. In Berea 9G) oy eas 
nall structures are frequently steel bolts as pivots. Pig. ie a 
shows an example of such .\(Steel bolt 47 mm diameter, etek) 
felt in the joint, leadb between angles and bolt. aan th cf, : 
Note 1LePeiiT. See Deuts. Bauz. (WAL. Sement supplenent. Ae 
The angles of the frame are .to be. dimensioned especially Ree 
rong and are to be reinforced, since the maxinun negative nom 
ents occur there. A sufficient number of stirrups is to be pre 
ovided. Joints in steel are to be avoided there, The ‘principal 
reinforcement of the ocean and of the post must be extended as 
far as possible into the other parts of the frame. Then the b 
beam can be partially relieved, since partial fixing occurs, 
according to Fig. 2/0. To avoid too great heignt of tne arch 
is advisable the use of spirally reinforced concrete as in Fig. 
2/3, particularly tN Abranamoti-Masid system.(Sce 5.49 as we- 


+? 


ll as Part 1). | 
‘Ine root slab particapates here in receiving the moments as 


| 74 | 
well as the floor slab with ordinary T-beams. Very thin slabs 
certainly have but a very small influence. strengthenine the 
Slab asin Fig. 207 on p- 93 18 frequently proper. The intlue- 
nce of tne slab is naturally zera, aS soon as it comes to lie 
h the tension chord. Development of the caves is shown én Figs. 
74, 275-6 
Frames with two Supports. ) 
Fig. 276 exhibits the system of a frame of 1666 Me Span cal- 
Culatea as a two-hinged arch with neutralized horizontal thrust. 
A similar frame, likewise with a tension member, in Fig. 277 _ 
is placed on a fixed frame beneath it. Notable is the frame 
With two hinges shown in Hig. 278 with elevated tie-rod, this : vie 
tension member having to receive concentrated loads here (clo-~ ee ae fre 
thes hung up in a club laun@ry). ~ | Ce Ce W ea deR a 
Note 1. Ve 418. See .B & Be 1912. iv. LON, 
Higs 279, 250 exhibit the treatment of the outer and “middie Ge OT aoc tie 
Sheds of the new Vessel Station in Persius St., Berlin. The - Re ihe ey 
Structural treatment of the truss of the middle Shed is evident ie os 
119 in Fig. 281. Its roof nas a width of 3. Om with 9.0 n between 3 
piers, ana the root prajects 20 at each side. The columns ore eg . 
hinged on concrete blocks and set on lead. ne regard to ‘the ee 
horizontal and vertical forces requires a ‘strong arched | janet £ 
ion of tne truss beams. rat bk lta a Giang 
A very important projection at one side is shown ne Pigs eho LAY ar ae 
by the hall truss of—Blicher & Ca, Diisseldort (Holsten Brewery, 4 | 
12 sy sons). 1 the projection amounts to 9.0 m i 
Note 1.00120. See B& B. 1912. .p. zee. 
Further see Fig. 297. ‘ Mi a ee OM “4 
ee other frame trusses with two piers, see Figs, 241, 138, yee i ee isa 
Frame Trasses with Middle Pier. en MES po 
Fig. 253 represents the cross section oz a street car snea 
for six tracks side by side. (Erected by Dyckernott & Nidmann 
Co). On the basis of a description, this Gesign proves. to’ bs 
more suitable and cheaper than a structure ‘in bricks: ar steeds 
fhe trusses hie 5.55 m apart. ihe covering is cor bosea of T-b 
Ceams and supports a root skylight with wired glazing. THe es h5 
arate foundations of the side posts as well as the eaves are 
connected togetner by wall beams. The wall panels are ot bricks 
iZ cm thick in lime-cement mortar. The upper part of the wall 


18 


s 
a 
ty 
Fd 


is glagea. 


/Al 


[AA 


72 | 
, A Trame with three fixed piers is exhibited by the hall truss 
of an oven hall illustrated in Fig. 284, erected by M. Pommer, 
LeGLpzig 
Hrame Trusses for Halls with 3 or more &isles. . 

The illustration of the system of a three-aisled nall is gi- 
ven in Fig. 235. The truss of the main gisles is a stiff frame 
with Ilxea piers; the frames of the side aisles are fixed to 
this but are binged at the foundations. 

‘the warenouse truss represented in Fis. 266 is formed by 2 
Stiri frame with binged middle posts; the prajecting ends of 
the upper beam rest free on the external .piers fixed at the 
bases. Distance between trusses 5.0 m. On the supports of the 
terrace side are corbels for a single tram rail. i 

NOVS Le Pel2i. Further see B & Be 1913. pe G2. 

Bis'237 Shows the cross ssction of the car and locomotive 
shea of the Salgburs Railway & Lramway Co. The roof of the mid- 
dle aisle 1s raised so far tnat admission of side Light is pos- 
sible. @ne total length of the sned amounts to 88 m, oreadth — 
32 WM, distance between main trusses 5.5 m, that of the secona- 
ary trusses being 2.75 to 3.25 m. The supporting columns have 3 
corbels to receive the beams for a crane track. Between the ce 
columns of the enclosing walls is a panel of brickwork 50 cm. 
thick. 

The nall illustrated in Fig. 288 represents a frame construc- 
tion without tension heam, but with foot ninges. The trusses — 
project externally above the side roof. Distance between trus—— 
SES 5.0 mu. Foundation blocks and feet of posts age so anchored _ 
togetner as to ieave a certain treedon of movement. The side : 
buildings are stiffly connected. Further see Deuts. Bauz.igi2. 
Gement Supplement. p. Zi. 

A frame truss with cantilevers at one Side and a continuous 

ventilator with skylight is shown in Fig. 289, erected by Max. 
Pommer Co, feipzig. . 

For the frame structure represented in Pig. (290, the middle 
span 1s formed as a Skylignt; the reinforced concrete slab is 
there replaced by a skylight. Zach main truss shows two inter- 
mediate trusses, that are supported on strong skylight beans 
and a hollow ridge team. The latter serves both to receive the 

skylight as well as to form a ee Notable are the great ier 
ns of the side trusses. (12.8 m). 

Note 1Lepei®ee. Bor the staticay cavculatians, see BE & Be. A913. 


Pod, 


\ {\ 


Litiy 
o 


LAN ft Art f 


yor, 


43 | 
/A3 Fig. 291 exhibits the use of frames with two posts and cant-— 
ilever. 

By Fig. 292 is shown the ‘cross section of a design for a man- 
ulactory, which in the side aisles has separate ‘intermediate 
gallery tloors. A similar plan is given in Fig. 293; itis a 
cross secticn through the side rcoms of the Concrete Hall of 
the Structural Exhibition at Leipzig in 1913, an erection Ly 
the cement construction company of Rudolf olle, Leipzig. The. 
lert siae of the illustration represents a section througn the 
floor, the right side being one through the truss itself. The 
distance between trusses amounts to 4.0 m. Poem 

A rich arrangement of a spacious skylight is shown by the b : 
hall truss represented in Pigs. 294, 295.(Also see B é iy OTIS 

p. 236). The supports, girders ana the corbelled slabs lying 
ween the skylights are exemuted in gravel concrete, the root 
One in the tension zone are of pumice » concrete. For better — 
sulation, each corbel slab received a coating of pumice mor— 
tar about 3 cm thick. The supports are hinged, excepting the 
wind portals of the end panels. a 
Kote 1.p-124. The HNolls in reinforced cancrete coost atl S woe: 


> 


> 


a 


rks \m* of area comeneds . the od | wUIVaine | (wooden shea. trusses | 
on iron columns) cost 40 morks\ m2 COveved. 
Porticos with single Pier. . (Railway Porticos). ek 

fhe roof surfaces are arranged either to ‘incline to one side 
or two and the middle. In the latter case (for railway portic- 
os), the rainwater leader can be carried down directly at the 
Support. for tne calculation of snow load ana wind pressure on 
oné slac, thecpiers are to be regarded as vertical cantilevers a 
fixed in the foundation. B a 

Fig. 296 shows first a clavtorn, covering With ‘eqns long : 

cantilevers, rigidly connected With the pier. The pier.is fixed, 
the adjacent wall receiving no load. Distance between piers hoy 
me The piers were connected together lengthwise by a stiffening 
beam. We. | 

MOS VepeiBhA. Soe PBOurtse. BOUT. Come SUlve Yeo 1620 

Fig. Z97 exhibits the cross section of a railway portico with 
Single pier and one with two piers for the Main hallway Station 
gi ab t Nurembe erg, built by Dyckerhotf & Widmann Co. ‘lo cover the 
4 rails are arranged three great porticos with two piers each, 

and four swall roofs with one pier each. the relatively aeep 

foundations were required by the necessarily great heignt. The 


74 

supports are arranged 10.73 m apart; they are calculated for 
the most unfavorable case of a snow load .on one side of the r 
root with a horizontal wind pressure at the same time. The col- 
umns were constructed to the imposts in imitation ci shell hit, 
mestone by a later scraping. Above the imposts the visible sur-_ 
faces were left as they came from the carefully dressed forms; 
they receivel merely a coating of cement_to which was added i 
milk of Lime. The length of the portico wita Single piegsswas 
about 16Z m, widta 7.09 2, thus the area covered bein’ about 
1240 ut. | 

Arched Trusses. } ; 

Arched frames with two hinges, 20 m clear span and 5 m apart, 
are shown by the assembling hall of the ship yard at Ansbach. 
(Fig. 298). fo reduce tne dead weight and for better insulati- 
on of the ‘interior, tne roof slat is executed in pumice concrete. 

Pig. 299 gives the form treatment cf an arched frame truss of 
the Ice Palace at Hamburg (with tension member). At the insid- 
es of the truss pliers are arranged gallery corbels projecting i 
Ze> wm. Also see Fis. 154. 
Note 1LepeiBde Also see Arm. Be. AVL. .§. S77. . 
[hb ohne arched hall represented in Fig. 300 (#reight House) with 
projections at each side is so far remarkable, since for the 
slabs on bota corbels as well as for the part b of the main s 
span pumice concrete is employed. All parts of the frames, the — 
longitudinal beams as well as the appertaining varts of the s 
slab are executed in gravel concrete. On similar freight house 
trusses, see Figs. 280, 286. : rps 
The new Cattle hall at the packing house ‘in Osnabriick (P. Ko- 
ssel & Go, Bremen) exhibits a middle aisle and two small side 
aisles (Fis.301). The root oi the middle aisle is raised to f 
far that a side light-is possiele.(Also see Fig. 287), but nin— 
ges are arranged in the middle piers, so that the upper part - 
of tne middle nall is separated from the substructure and for- 
ms an arched frame py itself. All feet are hioged. + 
Kote Aepet2o.Bor. the calculations, see Deuts. EBouze 1913. 
Gewme. SuppP. pe 41. 
Syglignts can be arranged according to Figs 302, 305. 
RY According 60 Fig. 304, the truss supports in the side walls 
are connected by strong horizontal beams (Machine House of Ci- 
to Garbage Kiln, Prankfort—a-li.e). -To the underside of the truss 


ll 


LP 
Le 


75 , te 
1s Suspended a vault for tne purpose of .producing a smooth un- 
derside. Pistance between trusses 5.2 .m. Above it is placed a 
wooden frawekork of the foof. 

Another aprchea frame, likewise with suspended ceiling and a 
wooden roof placed above it, is snown by Fig. 305.(Market Hall. 
in Stockholm). further care is devoted here to a side admissi- 
on of light. 4 
Note 1. pel2T. AVSO see B & Be. -1912. p0880, ‘ 
Cn the calchbhation of ‘frame and arch trusses sée among others, 
che works published by William frost & Son, Berlin: -- H. von os 
bronneck, Introauction to the calculation of the frames most : 
employed in reinforced concrete construction, and safe against igh 
oending. W. Genler, frames. Simple procedure ‘for calculation oe 
of frames of steel and of reinforced concrete ‘WibD executed ee a 
examples. Fr. Engesser. Calculation of Frame beans wita speci- ee 
al reference to use. pe 
5. Vaults. : tn aie eye : 
Plain arched roofs with tension rods, corresponding to the £ | 
freely supported curved sheet metal roots, can be eek A 
ing up to 25 mu. The roots are very ligot and allow rebaining ae 
the usual thickness of the walis. The usual rise amounts to 1/6 a 
to i/f7 of the span. For greater spans | is recommended the anger 
tion of a network in the heunches and at the top, as. well as | 
to make the vault thicker toward the springing. (Fig. 308). 
kor small spans tne bearing and distributing roas are ee he 
in the zone oi the springing; yet also a double reinforcement | ime RL 
at the imposts is always advisable. The horizontal thrust is Poy GO aa ey 
received by anchorea supporting rolled shapes, or by separate _ im 
steel beams, that are bedded in the supporting wells, and are. 
made fast against bending horizontally. They receive GRE: Gare ae 
ust of the vault and transfer it to the tie-rods, which conne ey 
ect together the impost beams over the interior. These tension ne 
rods may be suspended from the vault to prevent deflection (Pig. 
308), they way also serve to support lighting fixtures. For 1 © | 
larger spans are employed ties (Fig. 308). To have complete p 
protection from fire, the steel may be enclosed in concrete, 
(Fig. 313), separated from the interior by a Rabitz vault (Fig. 
315), or even be connected witn a usable floor (Fig. 324). 
every case special emphasis is to be .placed on good anchoring 
of the tension rods. The impost beams are stressed horizontally 


ee 
he 


pry 


[29 


/30 


76 

and may assume iorms as in Fig. 306; according to Fig.'306 4, 
the ceam serves at the same time as the roof cornice. -- bight 
may be admitted both through lanterns and skylights of shed f- 
form, as well as througn inserted glass tiles. (See Ds, O90 

Fig. 3507 shows the connection of a reinforced concrete vault 
of 19.2 m span with a brick wall 40 cm thick. (Woodworking Shap 
ot Brinig & Son near Hanau). The opposite longitudinal beams 
are connected at distances of 5-6 mw by steel tension members, 
that are again Suspended from the cuarter Points of the span 
of tne vault. On the calculation of va alts, ’see 6) 2 Gris 
pe 290%: | | 

A vault erectea by Franz Scnltter Ca, Dortmund, 1s represén-— 
ted in Fig. 306. The tension members are here arranged in’ pai- 
rs. The firm mentioned also builds artned roots with e doubled 


{=} 
| ad 


arrangement OL tne tension mempers, as evident from F1gs. £309 5 i: 
510. The main ties are usually at distances of 6 m, and are m-. 


made of angles, near the walls being bent apart as Side ancho- 
rs, SO that the Iree lensth of the impost beams receiving the 
horizontal tarust is: reduced to fe the distance Sh i soe the 
main ties (or usually to 2m). Ne a 
Note Lepet30. Kith a simpre 1 ee Ane. ble, ahede 


result for woofs of wide spans cormespandingly etrong tections 


for the Longitudinal beans, or short distances vetucen. the. Pikes, hr, 


80 .a8 tO produce a considerable - Vncrease in ovidarns | moterials,. 
GS welt os an unpleasing appearance of. the SAEer Rae LUN ‘CONSeO-- 
Uence of .the close anchoring. | eo eet 

It is sometimes advisable to place the tension member cbigner, 
ixamples of arched :roofs with elevated tension members are pre- ‘ 
sented ‘in Figs. 311, 312. for the hall building represented in 
- 512 a higher interior was necessary for acousbic reasons: 
addition of a plaster ceiling below the tension rods was 
therefore not possible. In both cases the tension members ser—!. 
ve to support lightins fixtures. 

A vaulted roof with skylight on reinforced concrete beams, 
that are supported at distances of 4.7 m ty reintorcea concre- 
te piers (45 x 45 om) is shown by Figs. 313, 314.(Nachine Hall 
in Hanau). Tension and supporting members also consist of rein- 
Torceasconcrete, so that this construction -- opposed to the: 
wonler and Scnllter systems -- is entirely fireproof. {To rece- 
ive the horizontal thrust at the imposts serve 5 rods with di- 


aneter 


re 
diameter of 22 mm, that lie on the outer side ou the reinforced 
concrete beam. 

Fig. 315 exhibits the root construction of the Promenade Hall 
of tne baths at Johannisbad. The upper vault is the supporting 
vault. To. receive the horizontal thrust are arranged ties at 
aistances of 3-21 um. The lower sham vault is fastened to the 
cearing vault by suspension rods. This produces an attic for 
obstructing heat and cold, and protects the tension rods from 


aanger of fire. The covering of the roof is by sheet zinc, fas— 
tenea on wooden sheathing, laid on the concrete with intermed- 


late alr spaces. 
In the following will be described also some form of vaults, 
that a proper sense would not consiaer as roois, but only form 
tne cething below a steel or wooden roof. Such vaults are espe 
ecially found in the longitudinal aisles of churches. &s a rule | 
they age so strongly built as not only to support themselves, 
but are in condition in case of fire to rece ive the parts of 
the wooden root falling thereon. Yet they are built very ‘Light 


and thin, Since no roof load is to | be considered. In eae y 
nce of a greater rise the horigontal thrust is less, “wherefore” : 


tie rods are unnecessary. ‘The dimensions of the substructure 
ai Cee less, since the dead weight, is small. 


‘the tunnel vauit of S. Nartin’s Church in Ebingen diurtembb- 


ré) represented in Fig. 316 nas a span of 14.0 nm. Offsets don- 
gitudinally serve to receive the wooden plates of the wooden 
framework of the roof. The thrust of the vault ‘is ‘received ‘by 
norizontal beams to-resist bending, which are anchored to. ‘the 
wall. 


is shown by Fig. 317. The imposts of the vault are ‘formed as 
norizontal beams anda receive ike very small thrust, which they 
transfer to the front walls. 

Note LePe 133. See B & Be. 1910. .pe-323. 

With arched beams (rib beams) the vaults are divided into 
several ribs, between which the compattments extend as T-beams. 
According to Fig. :315, the combined ribs of a church vault re- 
main visible to tne observer tor therr entire height, but are 
concealed in Fig. 315. In the last .case the ribs are always 
stitfenead by cross deams where they meet the lonsitudinal bdea- 
ms placea thereon. 


A tunnel vault of smaller span (7 m) and injemealCet ie fe 


78 

AU a Gothic church in Belgium (Figs. 320, 321) the ribs were 
trengthenea by 15 mm rods. The bays are reinforced crosswise 
by rods 6 mum G@iameter; the principal reinforcement is that, 
following the shape of the compartment and resting on the fade 
onals.(See B.& B. 1905. p.266). 

Fig. 322 exhibits the truss System of the new Church g Se Kar- 
_, 18 Kagdalene in Strasburg-i-A. (See B & EB. 1912. p. 73). The 
>7 system is like the buttress construction of Gothic churches, 

Excepting that nere in consequence or the use of reinforced 
concrete great external buttresses are omitted. ! 

Fig. 323 shows a rcoof ventilator almost 7 m.high, and Pig. 
324 is a combined roof and floor construction for a COW stable. 
The arched ribs here only form the Supports; the wooden roct a 
is placed on them. The room ower the stable Serves for nay and 
attic. (Live loaa 350 kil/mé )e A plane self Supporting floor 
would have required very thick external walls and substantially ; 
heavier construction. ine tension member lies in the floor; : ee ¥ 
the Supportine rods ase covered. 4 Rule Fie | :. ‘ 

Note 1.p.i134. See Deurs. Bouz. 1919. Sen. Eupo. bee oe eee 


ta 


Figs. 325,: 3260 show two exaucles of great ‘Structures 3 Sapaie 
nforceda concrete, Fig. 325 beins ta* ae eet fall ‘ini Ereclag: _ 
(Carl Brandt Co) and ce ae dai “Urusses” of. the evangelical ia 
% 


_Garrison Chureh in Cla. fivskeunosa ‘Widmann ‘Coe eo ae Oe 
Further see the frame. Constructions ‘trea ted on. Pay 15 ay Oe as 
6. Domes. se Ragie . oe i ae if ‘ Gott 
bomes in reinforced concrete are” eitner stronély - loaded sup- 
porting apmes or less loaged roor and crnamental domes, “such 
as are employed to avoid attached “Shan construction. ‘ney. ‘ere 
either constructed of rids ana panels or in the torn of ‘thin 
shells. The latter contain a structure of metidians and rings. | 
of round rods or rolled Shapes. Tne me na taes of the or ee vie 
taen has a network of thin rods. | | Pe se 
For the plain (compkete) domes, that have saual thickness b 
cetween parallel circles, the bearing ‘rods are arranged in tne 
meridian direction and the distributin’ rods as concentric nor= 
izontal rings, éS in Fig. 327. The horizontal thrast is recel- 
vea by &@ strong impost reinforcement corresponding in form to 
the distributing reds, that is anchored at certain distances. 
ouch Gomical roofs age Ireouently covered with sheet copper, 
what by special arrangements can be Wash and securely faste- 


nea to the lon 


mah se 

Rates 
May Lae 
1% 


/36 


79 
fastened to the concrete. 

At the Evangelical Society House in Dtisseldorf a rectangular 
room was covered in form of a dome -in the manner exhibited ‘in : 
Fig. 326. A cércular lantern rising 1.2 m high has a diameter 
of 5.0 m, and by means of a corbeiled ring beneath supports an 
ornamental glazing. On the top rests a conical skylight. 

Ribbed aomes exhibit a system of supporting ribs with compa— 


rtments lying between them. The bearing ribs are generally con- 


nected at the vertex by a ring resisting compression and bend- 
ing, as well as at the base by an impost ring resisting tensi- 
on. AS an example may be taken the dome of the Orpheum Theatre 
in Bochum of 20.3 m span, represented in Fig. 329; altogether 
nere are arranged eight symmetrically distributed double ribs. 
ihe section of a very remarkable reinforced concrete dome in 
3. Blasien (Dyckerhoff & Widmann Co.) is shown by Fig. 330 (B 
& H. 1912. p. 345). On a pyramidal roof with 20 sides and a 


or St 


diemeter of :33%7 m between supports, rests the smooth dome wi-y 7 


to 15.4 m diameter and 1.5 m rise. In the base ring at the im- 
post acts a tession of 156 tonnes. ine vertex ties 35 m above 
the tloor. From this reinforced concrete come is suspended an 

ornamental dome of Duro material. SE | 


finally, attention 1s to be called to the new Pedtat Ball da 


Breslau (qentenary Festival) represented ‘in Fig. 3o1, which i) 
exhibits a dome with clear span of 65.0) 16, phe greatest widta | 
of a dome in the world (Dyckernoff & Widmann Co). Height of t 
the domed ‘interior 40 m, clear width of the interior of tne b 
nall $5.0 m, capacity $,000 persons. — he 

ceclion EL. Applications to foundations ang Hells. 

A. Foundations. 
If the building ground be pad or the loading is ieecen larry 


distributec, then a reliatle foundation is created by the con- 
struction of broad footings for piers and walls by mechanically 


strengthening the ground beneath (saturation with cement), 
even if solid ground is to be reached, by the use of wells and 
piles. In all these cases, thus both for direct as well as for 
indirect foundations, reinforced concrete can be employed in 
the most appropriate manner. 
Plane Foundations. 

Plane foundations especially offer very particular advantag- 

es over other kinds of foundations. They require but little ex- 


ie 


[3 


excavation, since their bottom does not lie deep, and the tran- 


“quite Varge, for.to a Vous of 4 kAV\ cn? correspands /On. the SOV 


ainary f{Loor therefore does not sufftte Nene» An. “the Least. _ 


‘porting points occur negative mapa with positive ‘moments at 


sition to the bottom Icoting occurs quite rapidly. Therefore 
they also require but little building material and are tnesély 
cheaper than pile or well foundations. furthermore they atford 
a uniform distribution of the pressure on wae ground and - hinder 
unequal settiement, since they form 2a united whole.+ eee een 
Nowe 1.-0-137, The Loading an. the foundorion foorringd Vs always 


0 Voad on the footing of 10. tonnes\m~. The. vhickness of (an Orr 


for ordinary conditions are to be considered the ‘following | i 
allowable values of the loading: -- : | ee a 
a. Soft clay anc very wet, fine-grained ‘sand, up to Be 5) ‘k/ond 

b. Loam, medium clay and moderately wet or ere sang contain- 
ing much clay, up to 5.0 kil /iem*. iN ae i 
Ceo; Gark, nara clay and ary sand containing little clea, Bp 
to 5.0 kil/om@. is ata a ae 
d. Firm layers of coarse sand, Ais eae 
Kil/on*. | | ore ae 

The footing slabs are calculated by regarding them as. ‘vests! 3 
on two or more supports with uniformly aistributed loading. fhe Bs 
wall masonry forms the supports and the un aifornly distributed — uid 
pressure on the ground is the loading ‘o. Then between the ‘supe 


eA 


them. < 


NOLS Be Yeo AW ih See Part ao 


332 ato Ge 

1. For continuous walls. (a, bt, ¢). 

2. For rows of piers. (d). 

3. For isolated piers. (e). 

4. In form of a plane, ritbed or arched slab extending over 
the entire ground plan. (i). cee ey feet 

Conclusions in regard to the arrangement of the sine Shi 
nt are given by the examples of plane foundations illustrated es 
in Fig. 332. Pigs 333 ¢, d, assume the immediate vicinity or a aS 
an adjacent building. A decree of the Berlin building office . 
(1912) requires in this case tne following. (Fig. 334). 

A. By gradually widening the footing of the support at On \ | ie 
angle of 60° may be assumed a uniform distribution even for wet ens oe Ming) 


gage 
Pee 


(39 


> 


Si 
footings projecting only at one side. 

b. In the arrangement of separate footing slabs care must be 
taken, that the slab is made safe against bending, and that t 
the Dending moments occurring in the pier or support Shall pro- 
duce no separation of the slab from the pier; hence a reinfor- 
cement of the support or plier is necessary. Placins of wall p 
pliers without reinforcement on reinforced concrete slabs praj- 
ecting at one side is therefore not permitted. 

If the load of a continuous wall-is to be received, then the 
pearing rods are placed at -rignt angles, and the distributing 
rods parallel to the line of the wall. Longitudinal beams with 
reinforcement as in Fis. 335 prevent an unequal settlement of 
the wall. Doorway openings and special concentrated loads are 
likewise to be cared for by a corresponding arrangement of mo- 
re or larger reinforcements. the wall loads also make advisab- 
le a strengthening of the pressure zone. Gellar walls are to 
extend 30 to 50 cm belew the cellar floor. iM 

According to Fig. :336 lines of piers are to be connected by 
a continuous beam. (Arm. B. 1919. .p.187). 


In footings of isolated supports, both kinds of rods, bearing Re 
and aistributing, fulfil the same purpose. The addition of di-7 


g€onal steel rods may present certain advantages here. (Fis. 
337). The footings of a steel column in reinforced concrete 
are snown by Fig. 339; see Otherwise common kind of :footing i 
ls evédent in Fig. 338. 4 

Note Lepei39-. in PAs Ate lens to Footings of *the supports, OLS0 
S22 Pe Si. . 

A concrete slab covering tne entire ground plan ‘is tnen -rec- 
ommendeajfifithe ground can be loaded as little as possible, 
if one can no longer succeed with wall footings as in Fig.335, 
if tne face of wall and lot line coincide, and if with a strong 
inflow of water, it is desired to avoid pumping out the excay- 
ation. Too thick slabs are suitably replaced by T-beams as in 
fig. 340. It is staticaliy preferable to place the strengthen- 
ing rits on top, aS shown in the ‘illustration; then is necess- 
ary a-tilling for the cellar tloor. If the ribs lie under the 
slab as in Fig. 341, a filling for the cellar floor is no lon- 
ger required; likewise the forms for the ribs are saved. 

In Figs. 342, 543, are represented the’ cross and longituain- 
al sections of a box-like foundation for a building with wedge- 


a , eal 


ya 


[48 


52 

Shaped footing siab and ribs above it. The border walls recei- 
ve tne load of the main walls. Such a kind of foundation ‘is 
then suitable, if the foundations of directly adjacent struc-— 
tures make it-‘impossible to extend outside of the ground plan. 

In rebuilding the Color Manufactory of Gtinther Wagner, Hano- 
ver, tne foundation was formed of inverted cross vaults as in 
Fig. 344, on whose imposts stand the piers. The water level in 
the soil lay 1/2 m above the bottom of the foundation. 

According to Fig. 345, the compartments between the ribs are 
formed as segmental arches. 

Figs. 346, 347 give two examples of toundations for towers, 


and indeed Fig. 346 is tne foundation for the Tower of S. Kark’s 


Church in Stuttgart. + The slap covers an area of 144 mi and 
is ribbed crosswise on top. The tower itself is 56 m high and 
is built of reinforced concrete; stiffened by 12 ribs on the 
opposite vertical walls. 
NOLS —LepelA2. For churches. the tower foundations are always 
separated Fron. the other foundations. 
Machinery Foundations. . 


Great foundations for machines are to be separated as far as — 
possible from the proper construction of the building, and pla- 


ced on separate footings, particularly if strong vibrations c 
cause a settlement of the foundations to be feared, Disturban- 
ces of the work may have indeterminate consequences; a perman- 
ent and quiet running of machines must be ensured. for more s 
sately receiving shocks are generally advisable great masses; 
tneir ‘forms depend on tne kind of machine. Also great emphasis 
1s to be placea on suftficiént anchoring; the lengths of the a 
anchors must correspond to the thickness of the footing there. 
Fig. 348 exhibits the form or the foundation for a turbo-ge- 
nerator plan furnishing 2500 kilowatts, constructed by Wiemer 
& Prachte Co, Dortmund. (Also see B & B. -1912, p.421). fo avo- 


Sheed yo Mead aioe ee - : 2 - . 5 : 
‘iad the disturbances of the working, the foundation is entirely 


separated from the used floor of the machinery room. 

Many machines (for example, rotary machines, Diesel motors) 
produce quite considerable noise and vibrations, load tne vic- 
inity,and endanger the duration of the footings. Therefore in- 
sulating materials in the form cf elastic layers are employed, 
to Liwit the vibrations to their origin (the machine). If mach- 
ines (for example, compression presses) must be placed on a 


83 


reintorcea concrete flcor, then is advisable placing a layer 
rs between the machine and the insulation, which also. 


iy 
ed 


St 


ing & corresponding resistance. 


proauces @ good uniform pressure. 


cee 


tinke 


Leelt 


The insulating material mu- 


be sutficiently elastic, Strong ana durable, possess-— 


Ken frequently employ sheets 


Telt, put these have not always proved Suitable on account 
the etfects of olls, fats and lyes. t indeed cork layers D2 
nave las 


ural cor 


placing, ana; 


ela 


StIGL 


Xote Lev ve es [ANN woterials placed under CG ae! 


tea best, 


k let inte iron frames, which 


ty ana resistence. 


a preticularly or cork foundation slabs 
Zorn Co, Eerlin. The latter consist of cut ‘strips of 
resent open Jeints 
give tne Slabs a praca ene neat a 
slabs are especially satura ted to prevent the entrance ar 
er and cther destructive causes, as well 


pherance. 


OE 
nat~# 
inne 
thee 
wat= 
aS to increase the 


ore also LOO nelastic. For exanpre, fever Ae wade word ‘@WOUGH — 


to suffice for loods of 50 kivlon*. 
pressure of 2 kit\on* 


Note 2B. 


NOt ta be feared. 


5 


© 


'@) 


Tne Keinforced concrete piles are mace in the immediate vicin- 


Vaults ane Stiff Frames for ea Loads. 
these are preferably employed, 
but this must receive no hew loading. 
\suco cases ali main and division walls must be carried, “ACH 
seal to Fig. 350 a parabolic arch ‘is employed ‘for this. “pur-~ 
“pose. Tne hatcning in the taths Bee eres indicates eae existing : 


ror example, 
. anal must be built over, 


ncrete 


Pak 


canal. 
Es made ‘in a factory. 


O.143. cork 00d As peru elastic, 


Ve but Sselaow exceeded. 


_yuvversastion As a 


Viaia 


‘af an existing — 


But An actual practice A is 


ity of the building site or on the working yard of the Ge. In 


thelr use on the 


rivers; 


& 


curate 
plies 
aerric 


that are portable, 


Sité 1t 1s necessary to employ Special piled- 
can be rotated and inclined, making | 
Setting possible, permitting the noisting of tne nea-_ 


(welsht up: to 400 kil/m lins) without Suspending trom 
k. Likewise are necessary the proper windlesses and c 


correspondinsly great power machines. 


L 


i] 
te 


recom 
1.. Kor 


menacd in the tollowing cases. 


~The use of concrete viles | 


good soil lying aeep and a aeep level of the ground 


wuneretore where zor otner forms 
of earth are to be moved. 


a 


Ns oe 


etme 


foundations great 


a 


34 

z.- Por varying ground water levels, where wood piles appear 
endangeréa by lowering the ground water by sewerscot the regu- 
lation of rivers, and where reinforced concrete piles afford a 
substitute tor expensive wells or pneumatic foundations. 

3- For quays and docks, breakwaters, landing stairs, shore 
aqykes and other structures in tne water, where wood ‘piles : are 
injurea by teredos. + 

Note ~-HeiAd. Saturation of phe wood with creosote solution 
or by Thorouanry - Covering with broadsahesded Veron noils only V 
Vaperfecthy~ fulfirs. the day th hk better are tenped coverings 
of -tomped concrete. : . fe 

4. Bor very heavily loaded” structures with ody utilization — 
of the bearing capacity ana intimate connection #ito the foots 7 
ing slac. ae | 

5- For very deep lying good ground, which ordinary ee a 
es would not reach. | 

6. In all places where the excavation for the building must . 
ce enclosed by coffer dams, and where it is Trearea that aaa 
Cint buildings may be affected by escape or sand and. oy arty 
piles. 


by comparison of Figs. 351, 352,’ ane.cle ants cyuaewe the! ad=\ i, 


vantages of the new method for foundations. One recognizes hom 
4 een deeper it is necessary to go with wooden piles, if it be 
necessary to be below tne lowest level of the ground water, a 
and bow much may be reduced the number of piles by: the use of — 
concrete or reinforced concrete piles. x 
Tne making of the pile-is Similar to that of the piers in b 
buildings; it ‘is only to be remembered, that the pile must be 
equal to much greater stresses, since the blow of the ram pro- 
auces very high stresses. The piles mostly have triangular, s 
square or pentagonal Sections (Ztiblin system) and are seldom 
round (filled with concrete, p. 52), and are reinforced by rods 
like piers; but the bands are placed closer tcgetner, at least 
at distances equal to the least diameter of the pile, being c 
closest at the head and point of the pile. The longitudinal 
reinforcement of the cross section ( 1 to 2 p.c.) of the conc-. 
rete, first of all has the purpose to prevent the pile from b 
cending in transportation, loading and hoistinga Tne head of 
the pile must in general be protected from the heavy blow of 
the ram by tne addition of elastic and blow distributing mat-. 
erials, sand, lead, sawdust or wood. (1500 to 1600 kil with a 


é 
Teron 


ee 
tes 
ata 


HO 


OM, to’ Moy be assiened about a. ra ¥o O65 Won? 


85 
fall of 50 to 200 cm). Laso see Fig. 428. j 
At the point of tne pile the steel rods are joined together, 
(Fig. 363), welded (Fis. 357), or furnished with a steel shoe 
(Fig. 361). Men are often satisfied with a sheet iron shoe. 
(Fig. 363). If a water -jet be employed, then a tube can be in~ gf’ 
serted in the axis, through which the water is forced. 7 Ak; 
fne tamping of the pile proceeds at the place e of use oe he fern | 
tical or horizontal forms. Yhe first mode of construction LS) 
so tar preterable, in that the tamped layers are perpendicular ee 
to the action of the forces. Yet the use of horizontal forms i 
is more common; one then has the advantege or more convenient. ‘ he aera 
and rapid tamping. Mixing proportions 1 a ana he rd according |: : i ae 
to the quicker or briefer use, the aoe pees. for heads a fa Ei! 
and points. The piles must be left for. 4°to. oO WEEKS atter. making « ae} 
Piles are driven vertically,or obliquely, according to wheth— | 
er the stress 1s from the thrust of a vault: Ona vertical load.” 
A driver can orive 10 to 100 m dength of piles in 10 Bours of. 
work. The cost of the completely driven pilé, including deliv— 
ery of tne building materiais and the setting of ell mecnines, ee 
according to the exten@ of the lator and nature of the groun ndy 
is frox 25 to 28 marks. On reaching the hard pronnt Bo tne ‘Pile 
is allowed a load of 50 to 50 bonnes each. # ache ee ‘ 
Morte 1epethS. Usually 30 for as. the footing be not. too nore be 


Vine. the Load. By ae 
For tne deteruunateon of the bearing capacity | may ke ueployed 


Brix’s formula, which EE rata ae ea 


oe a See 

: a “#G)< 

This notation oe | 

P = allowable load on tne pile-in kil. 
h =:fall-in em, |) 4 


n = coefficient of safety = 2.00. yi 4 ay Be ae 

€ = average distance in cm the pile was driven ber stroke cm ih 
in last series. ee ty . : A) * 

G = weight of pile ‘in kil. : : Bi, a 

@ = weignt of ram ‘in kil. : % 


By Figs. 353 to 356 es evédent the use of viles for foundat- 
ions of buildings. The piles are driven in groups, and tneir 
neads are connected together into a single foundation. For hea- 
vy wail loads, one pile Cat pe grive, 


SO 

heavy wally loads one pile can be driven next another (about 
50 cm being the least distance apart), as in Figs. 353 a, G; 
Witan lighter loads a construction as in Fig. 353 b (also see 
Hig. 202) 1s generally preferable to one as in Fig. 353 a, that 
lacks the necessary stiifness sidewise, if no transverse walls 
exist. 
sxWitha a closely adjacent neighboring buildins, the first row 
oi piles must be arranged at a certain distance from it. The 
reinforcement of the footing then has to be as in Pig. 354. if 
he cellar walls be constructed of concrete, then may the fcot- 
Me be Ne Since the walls or tneir ower parts may be tr- 

cated as girders (Fig. 355). -- A combined foundation slab in 

reinforced concrete piles is shown in Fis. 350. 

Figs 357 to 360 exhibit the forms of reinforced concrete pi- 
les as employed for the new building of the Lower Court on the 
nedding, Berlin. Tne cross section is an ejuilateral triangle © 
with angles rounded orf. Ine reiniorcements are carried down Ks 
and combined into a blunt point by means of an inserted piece © 
of steel. Tne nead is cut off and is furnished with a strong © 
cylindrical steel shell 50 cm nigh and 2 cm thick. Petween whe | 

4B pile and the shell are placed segmental pieces of wood. The 
elastic cushion receiving the blow consists of a lead plate ‘ 
Ze5 cm thick Girectly below the head, a steel plate 1 on thick, me 
a block of end grain timber 5 cm thick, and a Strike slab rf 
Cm thick. | : 
According to Fig. 361 the steel rods extend into a steel snoe 
and are held by a steel pin driven fast between them. (Made by 
iid. Ziblin Co, Strasburg). An example of the combination of -r 
reintorcea concrete :pilés without correspondingly reinforced . 
footing is snown by Figs. 362, 354. ‘ 
fiven more than for the piers i the bullding must care be t 
taken for piles to have sufficient transverse reinforcement. 
it nas been established, that the preaking of a pile is gener- 
ally to be attributed only to the rupture of the bands,. Fart- 
icularly to be recommended in this respect are piles of spirel- 
ly reinforced concrete. They present the advantage of a partic- 
ularly great :resistancé to the shock ol the ram, so that nop 
protecting caps are necessary. fig. 363 sives as an example a 
piral reinforcement according to the system Abramotf—Magid. 
e Fig. 89 on p. 49). 
Piles constructed in the Ground. 


47 


(A 


Dé 


Yi 


o 


po 


/yo ® 


87 
With this sort of piles one is bound to no fixed time for d 
aelivery; he can .proceed at once with the foundatien after the 
award of the contract. fhe making of the necessary nole in the 
earth is done by boring (Strauss system) or by ‘ramming (Simplex 
system). Objectionable is the necessity for an éspecially care- 


ful supervision, ‘in particular .concerning the existence of sr- 


ound water, as well as the fact, that mechanical and chemical 


effects of the ground on the still fresh concrete -- so:far as 


no wetal case remains in the ground -- may be unfavorable. As 
a rule is also desirable here .a reinforcement, ‘indeed in view 
of a better connection with the footing (Fig. 305). 
Tne Strauss process consists:in this, that ‘in the ground to 


be strengthenedis .bored a hole and at the same time a Teed pi- 
pe is forced down (without pile driver). This bored hole:is t. 


then tamped with concrete, drawing up the pipe to correspond. 


Taus by neavy tamping the concrete ‘is forced into the cavities ~ 
of the ground and forms a cylinder, thatimay be in different ia 
diameters according to its strength, and which essentially in- Me 


creases the bearing capacity of the ground in) consequence of 
a uniform compressing of .the loose and yielding layers. or hen 


soil. The round bulges also supstantially ‘increase the bee 


and by the increased labor a pile results, - that possesses an 
most uniformly high resistance for its entire length. — . 


The number of noles bored may be increased to. correspond to 


the area of the building site. Hork can be carried on at. ‘once, 
for a:previous tamping ‘in special ‘forms and hardening before 


driving does not come ‘in consideration for the Strauss. piles. he 


fhe hole -is- produced by boring, thus without any ‘shocks. The 
appearance of the grouna water. presents ‘no difficulties; ‘bat : 
on the other hand any ‘ground however firm can also be bored t 
through if necessary. Then ‘is: added the advantage that for 


cach separate pile one abtains valuable data on the exact nat- ‘ 


ure of the ground ‘itself, and ‘further by the Settlement or the 


mass per unit length.of concrete tamped. ‘The heads of the piles 


are gokmed together by a reinforced slab, whose ‘reinforcement 
extends down into the upper parts of the piles,,forming the -p 


proper ‘foundation mass for the masonry placed thereon. 


fig. 364 gives a “comparison of the originally intended Ttoun—— 


dations (hatched) of ‘a locomotive shed with cleaning pit in 
3. Gall (sand ‘filling with tamped concrete footings) with the 


RO 


~~ 


8S 
executed Strauss. ile foundations. Fig. 365 shows the later ‘i 
insertion of Gace by means of a Strauss pile Toundation.  _ 
Gadoubtedly ‘in such cases bored ‘Piles offer ieee radvewtacda 
in consequence of the adsence of all driving. + 
Korte . ‘LepetBi. Both Pigs, ‘364, 363 ore taken from the authov?s. 


Besrven for .“Strauss pile Foundations in Swirtzerrvand.* Swiss E 


BOWUZs (BIZ. Voi. 59, o4 

Hurther see Gehler, eipaudee patent concrete pile. Nie aeneee | 
& Son. Berlin. a 

Kor the Simplex :pile foundation, a steel. tebe of 40 cm diam-_ 
eter with a cast ‘iron ‘point is driven ‘into the ground,and as ; 
the tube is -pulled up, the concrete*is deposited “in layers and 
tempéa -- just as for Strauss ‘piles. Instead of the cast ‘iron 
point, that remains in the ground, the steel tube may be closed 
by a so-called alligator paint, which opens” when eee up, a 
and the concrete is tamped in. 

Riles of steel plate: (Stern, Raymond, Jansen. systens, erect 
as @ Pule have conical form, Tne steel. tubes remain ‘in the ey 
ound; they are driven, either with or without. previously drive 
ing 4: pile. + | . ne 

Note 16p.452. For driven steer. tudes. COVE | shoule. ie porticu- 
Vorlartaken, . that. the Pont ‘Of the tube is. sufficiently strong 
Lo .penetvrate. the ground, and to prevent. whe- pee ae aie: | d 

Crane Rails on foncrete Piles. : ee ae 

4n example of the foundation of a sactuute bank crane ‘is: ree 

resented ‘in Fig. 366. -To obtain sufficient stiffness sidewise 

transverse frames are arranged on Pkt “piles at certain atevan— 
ces as‘in the illustration. : | 

Pig. 3607 shows a crane railway for ee HE Ae t 
the Aken Co. All piles were furnished with arrangements for i i 

Sinking with a nose. Here it was found better to. foree the WA hones, 
ter tarough the ‘interior of the ‘pile than. through a tube: atia- ie 
ched to the exterior of the pile. The pile frames stand at dis- : 
tances of 4 m apart. Further see B & B. 1911. ip. -217. 

On landing piers, laundry and loading sheds on :reinforced ic | 
concrete piles, seé Figs. 422, 423, 524, 525, as well as Kers- 
tea, Bridges ‘of Reinforced Concrete. Part I. pe 205. 

Sunken Wells. 4 RAVAN 

Sunken wells of reinforced concrete are masonry wells capable 

of resistance to externalsforces and chiefly require little “8 


choice, 


> Vaee 
ca 
t a 


\ i 


fits 4 a4 
is iw, » bid 


/53 °9 | 
/58 choice. To them is generally given a round cross section, and 
the walls are made on the Monier system. ‘They are sunk by ext- 
ra loading, filled with concrete, and then serve for founding 
buildings and bridge piers. 
The diameter of the well -is to be made sufficiently great, 
so that only the filling of the well and not the circle will) 
be loaded. 
A very remarkable construction with wells, carried out by. 
the designers fferner & Chopard, Hngineering Office ‘in Zurich, 
‘1s ‘represented ‘in Fig. 308. A-residence lay over @ railway tun~ — 
nel, but whose walls must. not be loaded more than was already 
the ‘case. ‘Tne difference in height from bottom of tunnel to c | 
celler floor amounted to ‘14.0 m. The ground WaS & good moraine 
‘in solid layers; the angle of repose was therefore assumed at. 
45°, Hor tragssferring the weight of the pard: of the building : 
next the tunnel to the required dépth served two wells 62:3, ny, 
external diameter, ‘furnished at bottoms witha strong steel 
circle. The entire weight of the building | was transferred | ‘by! 
reinforced concrete eircers, Valet? to the wells, acy oe 
the firm ground. 4 | oC ies 
Note Lepeid3. Purther see goncnege i: Reinforced: Foncrete 


Structures. 1941. Berns ve: | eg a P 
B. Cellars, a Getlare. CO ee ge ae 
The arrangement of dry cellar rooms is ‘often auene: difficult AR | 
on account of unfavorable conditions of tne ground water, pare es y): 
ticularly when the bottom of the cellar lies below the water . 
level in the ground. A later keeping out of the | water reaeires ae 
consigerable expenditure ana seldom corresponds to. Aapraee tai Ao 
One-avoids all airect contact of the concrete with the water, 6 
if the latter contains gypsum,.- Insulating materials are coat- ae 


ee 2 


Gite 


ings of tar, asphalt Slabs, cement. mortar - consisting of. r cen 
bape +2 to 2.5 sharp sand + 0.1 milk of lime (applied in 2 or 

3 coats, and after setting, covered by a thin layer of neat c 
cement mortar) tarred ‘roofing board» (strips lap ‘10 to -15 Cm:.o 
over each other and are.cemented with hot tar}, Siebel’s Asph- 
alt-lead ‘insulating sheets (2 to 4 mm thick of tarred board ¢ 
give the lead sufficient protection fro chemical, ake sata a 
and mechanical ‘influences) and many others. © 

Note 1. DetShe. See Kersten. Reinf. Sonce Sanstan. Port 1. 

First ‘in Pig. 369 is represented a cellar under a court made 
of tamped concrete. The maxamum live load amounts to ZO00 kil 


[99 


90 | 
/a* or an 8-tonnes wagon with 500 kil/m- for a crond of men. 
For the heavy Wagon was to be regarded as the maximum load 
3000 kil/m¢, and therefere- the thick concrete slab was pref- 
erred to the lighter and tninner reinforced concrete Slab. A. 
skylight at the end of the cellar provided for lighting it. ? . 

Kote 2ope454. For the Lighting of cellars wader courts is 
recommended also. the occasional insertion of gloss Concrerte 
Cevlindsy see p. 456. 

‘A two-story cellar arrangement -- ‘is shown by. Pig. 370. - Precau- 
tions against the entrance of ground water were Seibel hae Rah 
here. | ae 
According to Figs. 369, 370, followed the construction of t 
tne side walis of the cellar in tamped concrete. But ‘if a road 
runs in the immediate vicinity of the wall, then will the hor < 


izontal earth pressure .pe increased in ‘Important measure, ene 


refore a construction of the walli-in tamped. ccncrete would no 
longer suffice. Fig. :3Z1 exhibits the. ‘construction of such a ae 
wall in reinforced cancrete and strengthened by ribs. Gn. these | 
rests a transverse beam, which at the same time SCrves as. Bp Ol 
curb for the sidewalk. According to Fig. ‘372, vertical Monier 
arches transfer the horizontal forces to the. separate Piers 
Similar structures are shown by Figs. 373, 374s. According to” 
Fig. 373 (Kell & Loser, Dresdin), the ceiling is formed as a 


corbel slab at the show window. The enclosing oe 
crete wall receives an insulation next the cellar by a. ‘brick . 


wall 1/2 brick thick, and on the top ‘pean of the ‘reinforced 
concrete wall-is set-.a brick wall. According to Fig. 394. the. 3 


cellar has a prajecting granary, whose ceiling is arranged at a | 


the same height as the floor of the ground story, and also. ser~ 
ves aS a terrace. . . ‘ . 
‘The external - and light shart walls of the Paper Manufactory 
of the K6slin Co are shaped as ample retaining walls to. Becei-— 
ve a considerable arth pressure by. 2 loading railway slope ( 
(see Section C, 3). Another light shaft construction ‘in reinf- 
orced concrete i8 shown ‘in Fig. 380. ante 
If the cellar floor be only temporarily below the level of 
the- ground water, then suffices a watertight slab:floor of : ‘Te~ 
intorced concrete. Figs. 376. For a Stronger water pressure, t 
the upward force is transmitted to the walls by ‘inverted tun- 
nea or cross vaults. The floor is then always. to be leveled hb 


a 


91 
horizontally. Constructions of this kind are shown by Figs. 3 
377 to 379, as well as 344, 345. Fig. 378 represents a cellar. 
floor constructed by Wayss & Freytag Co. As in fig. 37/7, the 
#onier yaults rest on a layer of blocks 412 to 15 cm thick: 
the same manner the forms :for the cross beams are. formed ae a. 
layer of blocks or stones. ‘Ihe highest ground water ‘level abo- 
te the mused floor to be considered amounts to 1.10 m. 

Tf the highest level of ground water lies very much higher > 
than the cellar floor, then must the walls also be proteched 
toa corresponding height. + It is best to construct unitedly 
the entire foundation and supporting floor in reinforced con- 
crete as in Figs. 374, 380. The cellar then forms an enclosed 
tank: receiving a pressure ' from ‘the outside; cellar walls and 
tloor are combined to support. this. With, ‘6xisting masonry or 
concrete walls, these are best assisted by the addition of a 


wall facing as Figs. 982 a, b, that is intimately connected 
With the oe and is well anchored to the walls aS: “in ce 
Fig. 362. 4 | 


Wote 1.p-i157. Aso see Dr. Schultze. mpatertient ‘ogotnet jae 
Ground Kotere* Uw. Brust & Son.’ AGSae ee Oa 


Figs. 553, 384 exhibit the: ‘construction of a nabertigate boll a 
er house design. The” enclosing walls ADS OT, amped concrete, 


the partition, ceiling and floor slab (on a layer of lean. ma 


crete) are built of reinforced concrete. The’ watertight plast- 
ering on tne ‘internal surface is protected by a facing of | chin; 
kers, and that of the floor by an 8) cn layer. of tamped concrete. — 

The use of special means for making watertight is shown by ut 


Figs. 385, 386. As a rule ‘it is recommended to place such Mabe ek 


esials beneath the continuous foundation slab (Fig. 385), so 

hat this 1s protected from the entrance of the ground water. | 
As a layer beneath them serves: dean concrete about 10 cm tnick. 
According to Fig. 385 this layer of ‘concrete Peceives also. ce- “ek 
ment plastering with a good covering coat or ter: Over this -c 
come two layers of asphalt felt cemented ‘in the laps and on e 
‘each other with hot tar, afterwards painted with ‘it. On the ‘i 
instalation is also applied a protecting covering of cement 1.5 
cn thick, to protect it from injury in placing the ‘rods and t 
tamping the concrete. 1 t+ the watertight material be laid on 
the reinforced conerete siao as ‘in Fig. 364, this is no longer 
protected. To the advantage of the simpler examination later 


92 
and repair of the ‘insulation ‘i8-epposed the disadvantage, that 
‘it may be ‘raised by especially strong expansion. 

NOS -LepetSS. See B & BR. 1908. pe -130, 

bikewise the walls must be ‘protected :from the direct contact 
with the ground water. According to Fig. 385 ‘in the ‘insulation 

_, of the external walls, the asphalt felt ‘is replaced by Siebold’s 

I"? .pdghate. lantiagtatess Meus Auaulenien icc ranes to 15 cm above 
the highest leyel of the ground water; at this height the walls 
have a cast asphalt insulation against ascending ground water, 
with an external coating of tar to the height of the floor. 
Tae sneet lead insulation bisects vertically the external sup- 
porting walls at the maddle. More convenient in application, 
but easily exposed to injuries, is an insulating layer on the. 
exterior as ‘in Fig. »386. If the ‘insulation ‘be placed on the -in- 
side (Fig. 386 .a),then must one again consider the . possibility 
of its being torn off by a Strong . -pressure of water. The edva- 
ntage ol permanent control from tne cellar is. Ot Gen of slight 
‘importance. 

Note Lsp.idS. kecantly ruperosa dine 99) was been wach aaoee 
thot for protectton from injuries. wecewes a rich. COGtUNE bas 
the Heated cementing woterrval. a ae ; by 

Ce Walls against pressure of Wind, Earth or Water. < 

Note 2. PeolS% Division wolls ave tneated ron p. 53-%o 58; on 
ReBervo0rvr and silo walls see Section ILI Band Con buttress a 
‘ONG WINE WOLls. Kerstene Bridges in Reinforced Goncrete. Parti. | 

Hor discussion are detached walls, (enclosure and blind walls, 
target walls), :retaining and lining walls, bank and ‘quay walls, 
and ‘further also ‘reinforced iconcrete sheettpibing/theiasesos — 
which frequently comes in consideration for shore walls. 

1. Enclosing and Blind Walls. 
| Enclosing walls‘in reinforced concrete are now built more a 
and more, since they are cheaper and more durable than brick 
walls. The latter must be built disproportionately thick in vy 
view oi their architecturally subordinate purpose, and there- 
fore require dear excavations and extensive masonry in the ‘gre 
ound. Their construction may be of two kinds as ‘in Fig. 387. 

'bg &e Coastruction as a slab (corbel slab) anchored in the foun- 
dation, suitable for small heights; t and v are the bearing a 
and distributing rods. Heron 

b. Construction with anchored .piers with filling Slabs betw- 


Nay, 
” 
‘Soe 


/O/ 


/62 


93 
between them, adapted to greater heights of wall. Instead of 
continuous foundation masonry suifice ground ‘footings for the 


piers placed at certain cistances, while the wall panels betw- 
een these Support themseives. ) 


‘Since the wind pressure may come from either side, a» ‘corres- 


ponding double reinforcement is necessary. for the panel slabs 


of the mode b of construction suffices a ‘reinforcement at the 
middle if piers are set close. (Fig. 389). 

A suitable form for a concrete wall is shown by Hig. 388. W 
wooden struts -- set according to the progress od the concret- 


‘ing in the form -- .preserve the exact thickness of the wall. 
In placing tie concrete only 2 or 3 boards ere set above: each 
other, in order to tamp more conveniently, : | : oe 0 


A reinforced brick wall according to the Lehmann systen is) 
Shown Dy Pig. 389. For. Teinforcement serve slender bods in the 


mortar ‘joints. The use of I-beams :for ‘piers may be: seen in Fig. i a ae 
‘390. Compare this with the floor ‘construction according. to ‘Fig.2. 


At the building of the new Provincial Sanatorium at. Stralsund, 
was built a wall 4.5 to 4eG ii high enclosing the space tor in- 
terned criminals (Fig. 391i). This is perfectly smooth on the 
siae next the court, woile on the | exterior ° ‘LES divided ‘into < 
plinth, piers and ridge. To maintain the wail. vertically With — : 
certainty, about 50 cm below the surface of the ‘ground and eae. 


were : 
rectly on the tamped earth Was. es special foundation bre 


aces. | a 

Bigs. 392, 293, show ‘the srenpeice pod a ‘blind walls: on. ae 

tine GGrz-Triest. The wall bas the purpose of. concealing the. te) 

wagons at &@ racecourse. auloknee) of the Nonier wall ‘through 

out is -42Z on, height? fof piers 2.4 and 6.0 me + c; fe 
Note 2epeiGi. See Nowak, “Reinforced Concrete .an- ie: nee 

Vine in Austria. constructed by. tHe - AeK Raviucy Direction. Wn. 


Ernst & Son. 190%, 


Recently the different parts of reinforced enclosing walls 
have frequently been made in ‘factories, in order to save the 
Somewhat ‘costly work of the forms, as well as ‘in a given case ; 
to provide ‘for enlargement of the enclosed area or of the wall 
by taking apart and sesetting the wall. According to Fig, :394 
the pliers are grooved at each side and made Separately from t 
the panel slabs. The latter consist of reinforced concrete sl- 
abs 3 cm thick and 25 cm wide, inserted-in the piers after set- 


ting. 


AG 


ge 
“~e 
np 


94 
Remarkable is the Gividins wall represented in Fig. 395 for 
the Station of the General Omnibus Co in Berlin. The wall ‘is 
18 m high to’keep the noise of the motor cars from tne adjoin- 
ing area of the ground, which purpose is fully attained. To n- 
not odstruct passage of the cars were provided overhead corbel 
arms at distances of 5 m. 
farget Walls (for stopping bullets). 
For fortress structures walls come in qhestiod! siat. have to 
resist the impact of shots. First is recommended here an exter- 
nal layer exposed to the direct impact with a close-meshed wire 
netting near the surface to aiford a sreater resistance to ‘the. 
penetration of balls, to distribute the effect of. shots over a 
larger area, and to prevent an early breaking and flaking. of | 
the concrete. ‘fo the facing layer must. correspond a resisting | CANS Tec teste 
layer with stronger horigontal reinforcement, that shall Week hee: evs 
‘Ive the bending stresses. Eoth networks are to. be enclosed py ag ‘ 
rich conchete and are to be connected by wire ties. — Aa a Serie 
If this concerns only a protecting wall for shooting etaaaa, ee 
the direct effect of shots only come in question ‘in exceptions ei 
/63 al cases. Calculations are only made for wind pressure, Hee 
396 shows the construction of target malls: i: Holtenau near. | . 
Kiel; distance between supports 3 m; expansion joints are ges ae 
--vided at each 30 m. Another construction ‘is shown .by Pig. BG 
the distance between piers here amounts to 4. i Me See cae 
3. Walls egainst Zarth Pressure. | 
(Retaining and Facing Wallis). , iota re 
Retaining walls ‘in reinforced concrete are particularly RUAN a: aa 
able in sliding earth. They are to be calculated for earth pr- et eg 
essure and to be so treated, that’no horizontal sliding and no Ne at a ue 
overturning can occur, and that the allowable pressure on the ~ 
ground beneata be not exceeded. Construction | ‘in ‘split stone. h 
as the disadvantage of a2 considerable use of waterials, ‘since 
‘here the dead weight is determinative for receiving the press- 
ure of .earth., To increase the resistance, the face of the ret- 
aining wall-is generally given a small inclination tonard bes 


mass of earth. 
Wall Pzers with Slabs extending between. then. 
Pig. :398 exhibits such a construction. For simpler cases, I 
for éxample for loading terraces, ‘constructions with factory 
made piers and slabs may come ‘in :consideration as ‘in Figs. 399, 


a 


ERNE 
Cea 


by 


95 Bis | 
400. (Also see Fig. 430). ,ccording to Figs. 401, piers and ‘ge 
abs are rigidly connected, the piers indeed being formed on t 
the front side of the wall, so as to be better able to give a 
strong support to the slabs extending behind them. 

As for the steel reinforcemeni,othe Samé is true here as :for 
reservoirs; pressures becoming sreater downward require a cor- 
respondingly stronger Teinforcement, eitner ‘by closer setting — 
of the equal sizes of rods, or by choice or larger. ‘rods with 

the same distances. But in each case is advisable a greater be 
‘thickness of the ‘retaining wall toward the bottom, 
_dassive Walls with inserted Corble Slabs. h 
Big. 402 gives an example. The reinforced concrete corbel s ener 
slabs prevent a tipping of the rather thin concrete: walls By, a 
the load of éarth on them. | : SB na 
Angular Retaining Walls. shat ee ‘a 
‘Those of reinforced concrete, as shown ‘in. Bigs. 404 to 420, : 
have the special advantage of small depth of foundation. (as. a a 
rule about 1m), and as shown by Fig. 403, a more economical 
use of the structural materials. The base is made very wide, | Se oe 
0 So that the dead weight of the earth acting thereon may be we 
dé to resist the horizontal thrust of the back filling. Such | | 
an angular wall acts on the sround ‘just like an. ordinary ret— 
(65 aining wall, The unit pressure of the front edge of the well ve 
Gan be :reduced to the allowable limit. ‘pressure | _by the. arrene: 
ment of a front projection (nose) at ‘its lowest. part. | ee Ke 
Projections as shown in Figs. 403, 417, 418 also. afford good 


/of 


solutions ‘in economical respecis. Pema Ue A Re ae Sa 


Fig. 400 exhibits various treatments of the wari la: TEE ek 
‘aired by the earth pressure increasing downward. With uniform cS 
thickness of wall (a) the bearing rods are to be set closer dG tS 
downward; ; with: thickness increasing gradually or by offsets ee ee, 
downward '(b, c, ad}, uniform spacing of the steel may extend Uitte sk 
the entire height. If the wall be:resolved into a system of 
slab beams (¢), then with uniform distribution of the robs, t 
the filling slabs are to be maed thicker downward. Slabs of un- 
iform thickness assume a closes distribution of the ribs. | 

Particular emphasis “is to be placed on good drainage.(See 
Figs. 409°f, ¢). If necessary the back of the wali receives 
two coatings of tar, and next the wall ‘is placed a thickness 
of coarse gravel sand. Ihe most dangerous loading of the wall 


> 


aid yy © 


96 
occurs during freezing and thawing of the back filling mass. 

dn Bigs. 405 to 414 are represented various forms of ‘retain- 
ing wails, Attention is pabticularly cadded to the following: -- 

Fig. A07 “Bhe | “aprons” .extending ‘into the ground oppose a s_ 
dvtgede. of the wall (dar xample in saturation of. the ground 
beneath). 

Fig. 409. Retaining wall with two horizontal slaps for a ipar- 
ticularly great consideration of the back filling. The base s 
slab is stiffened by ehdhlwe iy beams; the second slab‘is a 
arched. ue ; 

Pig. 412. Tae load on the upper broad horizontal slab ‘is tr- 
ansterread by ribs to the base slab. 

Fig. 413. Quay wall with ‘sheet piling and platform on piles, 
from which rises @ retaining wall stiffened ies Pibs.-~ as aic: 
continuation of the sheet piling. . 

Fig. 414. Retaining wall with slightly extended base but st~ : 
rong anchoring. The upper part of the wall: Inay be ‘daclined | ba- 
ckward -- as shown. (Fig. 431). ) were eth iid 

In deciding on the reinforcement necessary ‘in the aittedeue 
structural members, tae following points of view are ieee 


/66 


ative:-- the wall has to receive the horizontal earth pressure, ts 
and thus is to be calculated for bending. (Distance between ORRT Ee Ne 


ports = distance between ribs). The horizontal bearing rods l 
lie in the middle of the slab at the front side of the wall. 
Distributing rods extend vertically at distances of 10 630. 
ou and are connected with the bearing rods. The main ribs form 
slab beams, that are to be reinforced by tension. rods. The ‘ch- ns 
ief purpose of the concrete in the ribs ‘is twofold, the stiff- 


loY 


ening of the wall and base slah, and the. protection of the ten- 


Sion rods. Tne small compression ribs at the front edge of the 
wall (Fig. 418, TEN are to have compression rods at. the -incli- 
ned side. The foundation slab is supported by the ribs and is 
stressed in front by the earth pressure ‘from beneath, at the 
‘back by the load or by the difference between the load and the 
earth pressure. Accordingly is to be made the arrangement of 
the steel reinforcement. . 

Some examples of the arrangement of the principal reinforce- 
ment are presented by Figs. 415 to 415. In Fig. 416 the bearing 
rods of the wall slab are omitted to obtain better supervision. 
Figs. 445 represents a construction of C. Brandt Co., Dusseldorf. 


97 eam 

Long walls. Tequire the arrangement ise Separating “joints ‘in 
the middle of ribs and panels. For double :ribs ‘is ‘recommended 
an indenting as in Fig. 419 e. On the outside the ‘joints may 
be covered by buttresses, which at the same time animate the 
front side . One ican also arrange a covering of the -joint a). Be ae 
strics of sheet metal or overlapping strips of roofing felt. 
tne joints themselves are to be filled with tarred felt. 

On bridge abutments ‘in form of angle retaining walls, see 


Kersten, ‘bra eS in Reinforced Concrete. Fart I. ip. 76. An 


example is shon ‘in Fig. 420, 
Ketaining Walls of Special Construction. 

‘These are presented ‘in Figs. 421, 422, 423... | 

Fig. 421. The rétaining wall is here ‘connected with a stiff- 
ening frame. (Promenade Hall at Borkum; see Deuts. ‘ 1912. 
Cem. Supp. p.--i29s). 

Fig. 422, The: retaining wall-is canpeetca oy an unlosding | 
cridge. (At High Tower Harbor in Bremen). i . | 

Note -1speics. B & Be 1908. Dp. QSeou nm Peta a 

Bic. 425. ketaining wall: with openings left Lees a bore ieee 
ane railway with 6.0 m distance between | piers. Under the conn- 


ecting beams the earth has its natural slope; thus a ica oe 


tion of a pressure of the earth ‘back: filling does not act on 
the wall. | | oe nie 
Note ZepeiSs. Gane a the .edvoulertos a a this > wetatning aR 


Mab, S02 AW. Be. -1910. Pe 209, a oe Bi re mae ae 


4, Sheet Piling. 


Sheet piles of reinforced concrete. nore; more drat sh than pe OS 


oden timbers and permit a better construction of the piles. 1 foe) 
Save ‘joints, they may be made up to im wide. ‘Jointing is. com— 
pulsory and may bein various: ways: according to Figs. 424 4O- 
425. To better stiffen the walls serve Special meter piles as. he 
in Pis. 424. ‘ 
better than angular joints are tongues and grroves with dif- 
ferent radii as in Pig. 425. Semicircular grooves asin Figs. 
426 are filled with cement mortar to make them completely ti- 
ght. Fig. 427 shows a necessarily tight joint (according to 
ibang) with round and hollow steel bars. (a, b). 
fhe piles are generally tamped lying on the wider side. Dri- 
ving is sometimes done as for driven piles: Oy ae using 
a wooden driver, which may be made as ‘in Fig. 428. = 


A 


Kok 


98 

Note Lepel69. AVSO see B & Be. ABZ. poShy 1913, 2.230, also 
DYeurtse Bawze -1AVOS.Geme. Supyep. Bi. 

/YO In hard ground the piles require shoes. Reinforcement is by 
longitudinal -rods and bands; on the latter ‘is to be placed sp- 
ecial emphasis, as for piles. The completed driven sheet :piling 
as a rule receives a cap at top by a horizontal bean. (Plate). 

BPurther see the followings Figs. 431, 433 to 434. 

5. ialls against Pressure of Harth and Water. 

(Ramparts, shore and ‘quay walls). + 

The advantage of reinforced concrete for the construction of 
shore walls lies first of all-in its favorable behavior in va- 
ried depths of water. According to Fis. 430 concrete piles are 
driven at distances of 2.5 mn, concrete BLApS being set behind 
them. The piles are connected by a cap. 

Por a greater neight of wall may be used tension anchors as 
in Fig, 431 (and 414), to prevent a separation toward the face.” 
In simples cases suffice for the parts above water lor reinf— 
orced concrete piers with slabs set between them (Figs. 431 a, | 
b). Thesconstruction of an anchor slab in reinforced concrete 
is shown in Fis. 432. 


Note 1epetTO, On. the ‘Fastening of inclined walls see ‘Seokien ar 


IV. &PLGsS. 519 tO 522). 
Note Bepei We nOncenning. the catoulation of ‘owes wollte, Bee 
MONE OCHOKS, ZEWSe Te RL bau.» AQIZs>r Pe -1SB6. 


Notable is a Lock wall :represented ‘in Fig. 433 with. full ue oe 


il ad of an inclined wall. 4 oblijue piles and sheet piling are | 
- strongly combined with the covering slab ‘into a rigid : rene, 
rk. The cross section of the sheet Mota was Sak at y shown — 
in Fig. 426. | : 

Nove -Lepetti. Great ship canal, Berkin-Stetrtin. beck Ot Hon, 
ensaatene AVSO See .B & Be 1913. 0.230. 

For ‘cuay walls the sheet piling is placed behind instead of 
before, as in Fig. 434, being so far advantageous, since they 
can well receive the tensile stresses produced by the earth i 
pressure ‘in conseauence of the great resistance of friction. 2 
In this way may be saved tension piles. Constructions with sh- 
eet piling in front are indeed usual; see Figs. 413, 435. 

NOLS BeHeiTis ALSO SSO Deurtse. Bouse 1913. Comes Supp. HsV%. 


NO 


yes ip fl 


pe 


& 


bas ge N 


Seay 
2 


99 ; S 


Section III. Apphications in the onstruction of Fie! a Esa 

pes and Reservoirs. 3 | 3 Ce 
A. Pipes, Ohannels and Culverts. a Theil ici ik 
Bxperience has shown, that concrete is” suited ‘ine ‘the “ier Fae a ta Be teens 
manner for the constraction ot sewers aid ‘canals, thet, betore mee senate 


e 
z 


sewage and against the eiculen: ‘ot the treba tion ae 
abn sediment. Meck ih jee Soe as ) martatic, 


Gat udt jestecta: ‘oh concrete | are t to: be a 
[? A ded ta UuSe an ‘internal pry: ih ne 


ks ce a 
os 


in the treatment of the : tte tar 


Ay sid Sis, 
ae by 


intoreed ‘pipes. have the art ee 


eater stresses ‘By ‘external and iaborael: pressure baat: geo coh hi RON Ns 
ater pambiorres cc double reinforcement ia) saponaliy: ‘suitable. Ss Rae el 


NAY hi ee taal BR 
v, . iy: ya wc sake / 


[74 


| Ta 


is built ‘in place; the ‘reinformenents projecting from the ‘bos 


coverins of the canal Likewise follons: with | previously made ve 


-ABrVdée Guiverte®, Bridées, Bart Te A a a 


‘400. 
Fig. 435 shows the dangerous breaking ‘points under external .p 
pressure; the reinforcement must then lie .at the top and bott- 
om of the internal wall and at the sides of the external wall 
of the pipe. The cross section of the ‘prpe may ‘be cireular, | eSs— 
Shaped or elliptical. Its ‘construction may occur ‘in a factory,* 
or in the trench. In the latter case ‘Instead of the usual wood 
€n forms mgy be employed steel internal forms. eee put eae ae 
WOte Bepetl FS. See - “Brinciples | Gor @onstruction .of pines of du rae. 
oewent Pines,” estaovished, by German Gonerete Union. 4 oh Lanes 
To ‘increase the resting capacity. ‘of the pipes is. recommended 
& covering of fine sand or of ‘concrete tamped ‘ain outside 4%, 
aS shown in Fig. 439. ‘The thickness of the wall here auounts — 
to 20 cH with a pressure head of 20 Me oe ie os 
Ghannelis and ‘culverts ‘in canals. constrncted | of : pouteneca| 
concrete | spresent the advantage of more vapid construction, that. 
résuits in shortening the unavoidable disturbance of street. t 
traffic. xecution : occurs alnost exclusively at the site. ‘The 
channels may be open or ‘closed, in the’ last case. having a Pe 
tangular OF apched cross section. Pi, 440 gives: an example Of © 
an open canal, as well as. Fig. 44feonducting path ¢ on the mid- 
dle wall of an epen arrangement). “For high walls are pecomten— 
dats cross” —, ab the height of the ‘top Bae ek ‘the wall for 


ting the watt and a ohne ee the hte a ne ure 


cks (length 0.75 m). provide for the. ‘necessary conncetions. The 


covering slabs. ul eatteay eh Mimaeny 1 eth ot 
Bxamples of arched channelr ee subterranean connecting ‘pas—_ 
sages) <in bad ground are presented in Figs. 443; banned ‘the, | 
last case pile foundations were necessary. © aca aks 
Note ispsitd, Burther: Bae. the Secrtvan on i Guiverts® Aw ters: 
ten, Bridées, Part Ty Bo Zi, Bevages,” Bart hs es 205. -AVs0. Be 


‘The fact that’ reinforced. ‘concrete : possesses. an: Lentieely: meer 
ficient resistance to the attacks of hot smoke gases has given 
an opportunity. for the construction of smoke flues ‘in’ veinfor- 
ced concrete. * Big. 445 shows the section of such a flue of 
tne Zeadworks of Gailitz, which made ‘in ‘box form, must at the. 


ra 


So 


painted with fiuates. 4 Goats of Siderostne 


ndouel {tr Biseshetowsate: 20a edition, volune Ye ces 


_togetner. (Wucztows ki system). 


101 ie Pi fees 
same time serve as girders for spans up to-16 m Mixing Propor- We Are a ad i 
tions 1% *3. . 
Note 2 ctetTS. BEE Part Te 
‘Be Reservoirs for Fluids. te | 
Reinfopced ‘concrete | ‘being capable of Resisting tension appe- 
ars iparticularly adapted to the. construction of. receptacles an 
all kinds, especially tor water reservoirs. Itsspossible - forms | 
are unlimited; for. the ‘most restricted conditions of space ma- 
ke «possible. the greatest usefub volume, on account of the thin ic Ne OCS ST a 
walls. Where suitable sand and «pebbles are ‘to be had ‘in the view ji. hae Rae 
cinity, it affords especially. the advantages of cheapness’ and. eae ee eo 
of more rapid ‘construction. A 00d means for making be a me 
ight is an ‘internal coating 1 to -2 om thicl of rich mortar ep Es SANE 
1, whichis then smoothed with neat cement and can then hep er 
ter, testelin, or ae 
nagnesien~fluorsilicate are likewise to be recommended, but nD 
must be renewed’ from time. to time. For subterranean cosereaire’ 
is always advisable an- ‘insulation. of the. walls. “and ceiling fre 
om the earth covering | (0. Wa to 2.0. m bigh) ‘by a coating of asph- 
alt or tarred: Telt. But the main : requirement. ‘for making ‘perma~ 
nently watertight a reservoir is a stitt and. unyielding const-— 
raction of the walls. and ‘a ‘foundation | ‘free from 20big ctions. 2 
Note LepoiTS. For hue ees Man ios © nomete and a 


Tanks serving to contain chemical substances. mostly require 
an acid proof ‘covering, best a material Tike glass. Fig. 446 . 
shows a lining with wired glass, ‘whose he don (2) are melted 


‘Larger tanks are mostly” divided in two: upets: 2 they ean be ‘ 
moge conveniently cleaned and repaired. The tanks generally st 
lie beside each other (Pig, 448), for round tanks also. ema) 
mes being annular, ‘one within the other. (Pigs. 461). Pilling 
chambers as ‘well as ventilating caps” (Fig. 459) may also be Poe 
constructed “in ° reinforced concrete, =; | Pt A 

KOS? BepoiTWe ‘the PaYTLtLOn walle Jor" Long, and Wish waite coe ‘ 
also .produce a veauction OF . the yaa een monents cour ing | An 
Lhe .wal\s, 822 -Ppe XT06 | 

Reservoirs may be divided -into:-~ un 

&- Those with’ ‘rectangular (polygonal) and | round | plans. 


1 


yeaa Petal 


102 


[Y7 b. G@pen and covered -reservoirs. 


‘diversion of the gathering. surface water. 


(7 


ward ‘pressure ‘is’ constructed : @ continuous - weinforced - conorete es 


protecting layer of tamped concrete! as ‘in Pig. 464 -- as a fo- fi 


OnLy of ter. the | GOnpLe tion ’ OF. the > meserpotr and Gad ng. athe. cous 
ere sl}, since the. ier she's ond wes exert oO greater, pressure 
On. the ZrOund e thy x Pi. 7 ers ace Sa a RN 


Subterranean reservoirs, those on the ‘level ground, and — 
a tower structures (weter towers), or ‘in buildings. 
Reservhirs with :rectangular plans. | 
‘The best form of all -reservoirs is cylindrical. But. rectang-— 
ular ‘reservoirs .permit. better use of the Space; yet the nave | 
the disadvantage, that the angles easily leak, and a bending _ 
of the sides outward must be iprevented by the use of ‘thicker 
slabs and the addition of strong stiffening ribs. fo obtain: t 
thinner watis. is ‘recommended the ‘insertion. of partitions. oa 
tn good ground the bottom ‘can“be nade of tamped conerete veee 
to 50 \om thick). qd in .bad. sbil conditions and with a strong up 


Slab; the walls. are then: rigidly connected with the: ‘base slak, te an: 
which results in a reduction of the calculated necessary tie ey oe 
ness of the wall... Appropriate is a thickening and | extension On to a ae 
the base slab under the. ‘supports and wall: as. ‘in Big. 454 B.A Pee " 


undation -- ‘ss then always: advisable, Also’ necessary is” qcare. 
ful drainage of the. base’ ‘slab and | external walls, pad | also a , 


Note -LsPet 77. Lrt- Vs proper %O. vamp. ‘the plain conerere pase” 


we 


Tne external walls. may “be executed ‘in PM ienweds eshowete’ under F 
favorable conditions of the ground according to Pigs. 447, 445 
to 450. Reinforced iconcrete ° ‘is then | preferable, when ground. bale 
water pressure “is to” be’ ‘considered. ‘For the smaller banks” suf- 
tice slabs simply _becomong thicker’ downward; ‘larged reservoirs _ 
require “insertion ‘of stiffening © ribs). that as. a rule lie on t a ; 
the exterior. + (Pig. 451). Por greater heights | ‘appear ‘preferable RE CoS 
inclined retaining walls: ‘(also see. ps 165). The | bearing rods Pye) he: 
of the wall then run ‘horizontally over the ribs. (Fig. 451); w aaa oa | 
with the arrangement | of -horizontal ribs. (Pig. 452) the bearing 
reinforcement extends: vertically. The same ‘is. also true, if. sy ba 
fixing ‘into the base slab occurs, and the walls above are: ‘fixed: 
to a strong enclosing beam. Bach fixing naturally assumes: the 
arrangement of strong arches, which especially at the base me 
with a view to’a: ‘pertanently efficient plastering of the. inter- 


nal surface | 


hes | 


Pun 
Shaye 
ne 


nae 
LOE Te 
Were 2 


ako 
Raa ta) 
(us 


/?9 


external walls are made of the. same. But reinforced concrete 


403 : eh 
internal surtace-- is very much used. Fig. 453 shows the treat— 


‘ment at the angie of a :reservoir with arched walls beeesen, ver= 


tical buttresses. 
For thicker walls the flat side-ie first carried up tontall 
height, but the other side being progressively executed with = =. 
the worgé of ‘concreting. For small tanks ‘(troughs ‘for aininala); be ee ae Sd Pe, 
bathing pools and the like) are employed eypsum or also wooden Sed AA Ee ug 
external walls against which the cancrete ~- after: placing Ae) ha co 
steel network -- is thrown and tamped ‘from ‘the interior. af DR i OM kre 
necessary an internal fora is made. H atte eae ah 
Fertitions are only constructed of tamped conarete, when the hes 


is therefore already ‘more advantageous, ‘since in dimensioning — 
the partition water ‘presaure on one side must be considered, 
The slabs and ‘ribs are to be made thicker donnnard;, according — 
to Fig. 454 a the well is fixed at top and ‘bottom, as well as 
for the external walls. Fig. 454 b>? represents: ‘the partitio ‘ 
wall of an open tank (settling tank): with: service path, Be 
Fig. 4 ig ‘¢ ‘is: the double Wall | ‘of ' another ea tank, bad 


ration cries iy a ie ne io ie | 
With a tamped conerete. ‘base as ‘in Fig. .455,) one. nant coun 
a good ‘connection with the reinforced ‘concrete walls, ‘indeed ra: 
by specially ‘inserted reds. cand by the use of: eB | Ticher, nixture re 
for these parts of the base, — ve ey aes 
‘The covering serves as” a protection #rom ‘imparities Potts, 
etfects tid mARDAES without Mean a ais. iat, piace ee 


no idansladden. tink, then puhesun aie nabmeeian are mg x“ 

~~ assuming greater areas. The ceiling bas) to. support a layer» 

of .earth, the snow load or some. concentrated loads” ‘to be expeo~ 

ted; traffic loads’ seldom -COMG | in ‘consideration. — ok eh ee MUN Nu. 
For reservoirs of great area, that are exposed to ‘sunsrineg, Sait A ee 

separating “joints are necessary, that may also: be ‘the’ advanta- | a 

ge ‘for dividing the iprocess of construction, cand. ‘further make 

possible .easier: supervision and more rapid. ‘repairs. ‘The: Joints — 

are filled with tarred :félt; the connection of the separated a 

structural members: is/made by bolt or spring :joint, ‘or by over- 

alpping. (Also see sa ease 


PY 


ri} 


466 -f. 


‘104 
Reservoir with Gircular Plan. 
‘The cylindrical walls are only stressed ‘in tension ‘by. the w. 
water pressure, thus only reouiring a small thickness (6 to 8 


cm at top, 10 to“l5 cm at bottom); the annular reinforcement 
‘1s composed of horizontal -reds and the ‘vertical distributing 


rods. The annular :rods are set | closer domnward and forn a net- 
work with the vertical ‘reds; the steel --.on. account of ate Ri 
length ---is stressed to only 600 kil/en. agmte  e8 
The covering follows according to Figs. 458 to 460 by a that fe ae pee 
ceiling with or without intermediate supports. as ‘for rectangu NY, ON ata 
lar reservoirs, by a dome (Figs. 461, 463), of by 8 cond te 
roof (Fig. 464). The dome : requires a strong tension ring to ee 
receive the horizontal: thrast, but its. thickness, is soneealiy’. hs 
very small. ‘Even if reinforcement “is: often necessary by oe 
lations, yet for reasons | of suitability - ‘is Lae ‘employed a | 
reinforcement of at least De Date ed Uni 
emall sunken tanks ‘Mp. Yo about 200. roe capacity are. sonevines 
built in the ‘form of. hemispheres. Fis. nese rer such a ae al 
buction by Franz Schliter, pouty peas aaee, 


el 


a cleaning .pit and a shaft or: measuring the mater. 9 
For the elevated reservoir ‘illustrated ‘in Pigs, 461, 462, “t 
the chambers are) concentric, one within the other; capacity — 
1000 m2. Fig. 463 shows a tank 8. Om ‘in. clear width and 3m da 
deep, covered by a ribbed dome. The reservoir: of the Odorico . 
Co. shown ‘in Pig, 464 has a conical roof; Capacity 1000 i, ay 
Zf the floor bas a ‘base beneath, it can. ibe, constructed | as. a 
slab (Pig. 464). On the contrary, if, 4tcis freely ‘supporting, 
it has to bear the load of the water. Ut: may then employ the . 
form of a ribbed floor (Fig. 466 hy a cone (Pig. 466 b, 6), 
a spherical segment: (Big. .466 a), one with ‘internal sphere. and 
external frustum of: @ cone: (466 8) or a form according to) He 


a water depth of 2. hes In ae ee Oy each: nee ‘is. pong 


Pigs 466, 467 vival) an: example of ibe dunetraotien: pe bicsue 
eter with 22.0 m iclear: diameter. Such tanks must be permanent 
and watertight. ‘Reinforced *concrete ‘is particularly : recommend _ 
ed therefor, since the tank being open at. the top, “is exposed» a a | 
to the effects of varying temperatures. Se: 

, eemened tanks: in buildings and on special’ tranerork (Hater. 


‘ 
= 7 


‘105 
(Water towers). 3 Cah 
Examples of structures :for elevated tanks in “‘ipadidines: 3 are 
presented .by Figs. 469 to 471. Big. 469 shows a water tower w, 
with capacity of :30 m2, where the supporting floor at the same 
time serves as the floor of the tank; the walls are strengthen- 
ed at top by ‘f-shapes, ‘The reinforcement of such a tank may be 
as in Fig, 4/0. Pig. 471 exhibits a hot water tank with a sepa- 
rate floor, that has its own drainage, so that the use of the 
room beneath may not be endangered ‘by the overflow of. the ‘tank. 
ilevated tanks on ‘chimneys mostly iconsist: ‘or two concentric : 
walls and are supported by corbelled rings on. ‘the masonry Ofc 
the chimney shaft. This corbelled support may be direct and ) 
_ separate as ‘in Pig. Ap2. 1 or Nave the aid: ‘of longer ‘supports. wih 
(o, asin Pig.::473, which are connected by rings and whose | feet ah 
are cut ‘into tne side | of the chimney. a ‘For larger tanks must - 
be recommended special tower ‘frameworks as. ‘in Fig. 474, whose | 
piers extend down to the foundations of the: chimney. In all oo 
cases are to be ‘inserted ‘insulating material (asphalt feltior i 
air space) between the tank and the wall of the chimey. cigtee 
Kote 1. 96185. See: Ronebuch RR Bsewbetons 2 ma CS v 
Note 2s Pe 185. Bee Bo & Be ABAD. ive BB85 ” ae Caw S os 
For the proper water towers the pe aaa ie ‘ok age | 
onry or of ‘reinforced. conerete. Examples of. the : ‘first kind are | 
shown by Pigs. 475, 476, 477. The tank ‘may ‘be separated ‘from 
whe supporting floor :or be “i connected with ‘ite: (See. # 
Pigs. 469, WO) oS og coe. 
Phe tank ‘represented ‘in tig. 475 eantaian’ ah “ye ore | 
tank (Fig. 476) 160 0? The latter ‘is construction by Béhnler | 
Go, Stuttgart; on details. of the roof, see Figs. 229, pel06,_ 
Supporting framework of peinforced ‘concrete consists | ofa : 
number of pers, whieh are: connected. .by ‘cross | struts:ar ‘inter- 
mediate ‘floors. If one desires. theiframework | not to be. ‘@xpos- 
ed, then is employed a paneling any ordinary brickwork or holl-— | 
ow tiles as an enclosure (Fig. 478). The. piers may’ remain vie 
‘ible, ‘be combined | with the enclosing wall, ior be. entirely ‘cov~ 
ered by this. The supporting framework ag a. rule ‘is a polygon * 7 
or evel? a cincle ‘in: plan. The foundations of the piers are se- 
parate or connected ‘foundations | (also see Figs. 347 492)5 or 
by a single solid slab. (Figs. 346, 490).. 
(6 The tank-itselfis either rigidly 2 aneaaet With ae fraine 


\ | : . ey ; Ba a 


Ie e 


Py MO LY AR t) 
a ee ay rice ents 


peste tra 
framework, (Figs. 479 a, b, ¢, 4) or is separated from this 
a joint (Pigs. og a, ). The Vebaraiais amber ri. 


edi te with in fakbnaite! round conditions. 
‘The tank nis almost sah provided with : 


Sig? ciuewacak ‘suffices a ‘layer. we 
or even an reasaph bisnlend: bricks or of 


presents an ins es pido a 
exterior of the tank (Pig. 4 7 
in Pig. 466 care RO ‘longer | 


ae Pig. 479 bs ceded ah 


purpose of dividing te ehouar oarve, sup rt 
equal ‘parts. | th veg , ag ee 
Ascording to. Pig, 464, the shart ‘of the 
separate .piers, that. “support. a platiors 
tank: (45 3). Here. transverse cantilever bi 


iform quiets of ‘the bottom of bai me 


i Peat 


$4 


(94 


concrete presents side binad: and economical Seber e tat 
er sea nor spring waters. attack cement. Gontrasted with tamped 


(Pig. 494) afford the possibility. of ‘contaraction without hin-_ 


piers, that transmit the load directly to the ground. ‘The pies ge OP 


107 | | , 
ROVE Lepoi88. Generally in-che construction Of 0 moter. tower 
core for. the arahitectural OTF Scr must be. taken “An. VSTY - APIRS 
MENT MEABUNee Towers dowinate. the ‘BSUPTOURGLNES - Va Oo wide ONeOs 
Thay one always buili ina detached POSTER, wherefore. they, 
Ong Often More “Wmportant. than .Wouse ‘Facades - ‘AW .0 street Front, ah a ye 
Pig. 455 :c shows the skeleton of the tower of the tank struc- igs | 
ture of Wolfsonn Co, Breslau, ‘illustrated in Fig. 499 2. A “| 
Heonomical advantages, especially for low tanks, are . afford 
€d ‘by construction asin Fig. 486. The top of the tank wall. is. ; 
Tormed’ as a stiff beam; the malls are slabs fixed at top and — 
bottom with vertical main. reinforcenent. ‘(algo s see Fie 452). 
The tank has an- octagonal plan. + a A i | 
Note -1. Hsi89. AVs0 .see B- & Be: ASL2. pehOT. | ae en & 
According to Pig. 487, the terminal ceiling ot the shaft. of) 
the tower at the same time forms the bottom. of. the. tank. eat i; 
Separate ‘illustrations of a waver tower in ‘Egeln, 5a construc~ 
tion of the: Union,” Cem.dek, ‘Hanover, are ‘Presented in ‘Figs - 


ees es 
fer ee 


sg 1 VT, 
a ‘ 
3 


bert! gisesand. Hanover) ‘in igs. .49%, 492, the tank y ieee ag Fire 
ican Ana of steel in. the: at Lae rs vs 


concrete structures, the saaller thickness. of the tank walls 
as well as‘a. strong steel reinforcement reduces. the danger of 
shrinkage cracks. Separation ‘joints ‘betxeen the floor and tank 


drance - by «changes “in temperature. The: necessary heat * insulati- 
on of the different ‘bathrooms may | ‘be: effected | “hy: the use of be 
hollow walls and hollow ‘fleersa.” 24 ; 1€ 

‘Phe tank bottom constructed asa framework mostly rests Ou 


rs may have a connected foundation asin Fig. 493 a, : ( also: s. Ne ee 
see Fig. :336 on ip. 439), or have separate ‘footings as ‘in Pig. a 


493 6b. The distance 1 ‘between the piers may then be made least, e i 


where the greatest depth of water exists. Thin piers can Beat: 

participate in elastic pendulum movements. aE Se 
Fig. 494 shows the treatment of a swimming .pool with capaci - ao ie 

ty of 510 >, resting at but three points on cast steel ‘ball. i eles ee 


bearings. . Peay 0 HGS 


‘ee I et | MG 


19; 


ceiling of the moving ‘ pieture theatre. (Metz). + 


Glazed tiles: (blue, white or green) give the water Zi hatha: euly 


MAVCH KAS OS -O nesult, | Abort. she. ‘Wires. Send. xo. expand more | etre 
‘one. ‘than. the bah gant bed a be aya. ‘ 


108 
‘Thése .are so eagiiedhad: that. each receives approximately 
the same load,. ‘A The walls are shaped as bearers. 
Note -1. PelBhe: Burther see Peurts. Bou. AQLZS, Gen. BUY 9428. ( 
Sections of other constructions are to be seen in Bieay 495. 


496. Fig. 497 finally gives an example of a perfectly rigid c — 


connection of the pool with the construction of the ‘building... Cs 
The bottom of the basin bere serves at the same time as the | Co 


Roe ids wHeh8S, Sees HB. 10095 9-860. 7 He eae 
For swimming pools generally suffices a coating of the ‘inte-' GK Se Ae rea 
rior with a ‘sucothly. polished | ‘coating of cement. plastering. ¢ ; 


color; but it ‘is. Gifficult to prevent ‘separation of the. bottom 


tiles. “ Se ce ee { ee Mt sina 
Kore. 2eps19Ss By OOMITTANE NOt water. the Wee ‘ore seated, 


faxing Ghanbers. 
Bor tarbine chambers 


before all is’ ouliaceals when "space Af Liaiyea, and at tig iend | 
weight of ee must be restricted on account t of | d gr- 
ound. ane iN hee Cental Sai 
‘A turbine ohauner’ constructed vinan, eriiaend ‘building “in Als 
{nann (after the design of Bd. Buiblin, Sereabura? ‘is. ‘shomn in 
longitudinal section by Fig. 500. a | a 
Cy Bins for retaining Solid. Ae | 
Fig. 501 exhibits the treatment of a rectangular bin for. ti- es 
me. The lime ‘is slaked ‘in the bin,and only this ‘is ‘removed — er 
through openings in the end wall -- when ‘itis: Slaked and stiff. | 
the openings are ‘closed by horizontal planks :resting on each 
other, removed according to the use of. the Lime, * ek i 


Korte ZwPw LQG | “Abs B00 Bo & Be A910. pe ehitees 
Por ‘ice cellars ‘Is recommended the 


Ck 


ne, 
Wy 
okey 


PS 


yar 


JIG 


/ 


IF 


74 


Out odor and cheap. s EMEA I ee rear Ne 


ashes, ,ete., or grain ‘1s stored and can: ‘be discharged. through cee 
funnel-shaped: outlets as reouired. Here ‘it: ‘is to store on. the fe ae 


‘109 
For ice cellars ‘is ‘recommended the Niead daueet ‘of two separ- 
ated walls, only connected together at certain distances, the « 


‘Spaces between them being tamped with dry insulating materials 
(for example, peat dust). + Likewise ceiling and floor are to } 
‘be insulated correspondingly. Air spaces are less used for ‘in- 


sulation. Fig. 502 shows an‘ice cellar design ‘for the Bavarian’ 
Feat Pust Works. Other arrangements, that are entirely perman— 


ent, contain “insulatéon ‘by pumice ‘concrete, pumice gravel and i diag Tae 
pumice lava slabs. Brequently the external wall’is builtiofo = = 


ordinary masonry, only the inner wall. mele) fiat ‘weinfopced cons a es A. 
crete. Purther see iB & EB. -1913.. p95, 245e/0 04° 4 es PE ae a A) ge NEO 
Note 1s~si 8%. Boot dust doesnot would or Aeconpose, “te wAthe 


ye 
ae 


levator Bins. (Silos). ee tao be 
Klevators are groups of great. ‘bins like athe do sinew! ir 
masses in fragmants (sand, gravel, crushed stone, | ‘coal, ‘ore, 


ei nee area Bn | | anata ‘possible volume of ‘the si aatow 


one, .etc., oe those fem @ravel, aaed: verushed | en tao 
and even ‘into cellular and dares 4 bin. Coo 
construction. 

Cellular elevators are parthouLdes: beets bal ‘fox storage of 
drain. They have at top a ceiling closing the | ‘bins, which at 
the same time forms the floor of the attic, where the’ heistig eran 
and cleaning machines -are : placed. ‘Ab the bottom ‘ek the bins mie ah: 
are closed by slides. ‘Advantages of cellular elevators; anaes ye 
area required, cheap ‘in construction and use, simple mechanical 
filling and emptying. he separate bins are mostly rectangular 
shafts in .plan.and have doubly reinforced partitions as in Fig. 
503, since the stresses ‘in them may vary, according to whether 
one shaft-is empty and the adjacent ‘is full, or tonverselya I. 


In greah elevators no separate enclosing walls ‘in brickwork .a. — 


are necessary; generally suffice the outer bin walls built of 


\ | 


260 


oA 


bins; - i i ed ee 


mass as for " ie form the. necessary. bi 


(“Goal bunkers”). 


: -110 
reinforced ‘concrete. 
Other forms nda plan, with and’ without a facing 


of a eatiecse elevator ° is. i avbasbe ‘in Pig. 504.1) in the: er 
lie eh Aaa -srseint me square Weel SSretaen ones: with arched , 2 es 


dor lul ihe aie dost sidabadedes eee all 
Note -Lsp-192. Arso jad ema cn) lag thas ate 2nd coe 
Yove Ce Pe Ade * : i 


| | ae Sy 
Fig. 505 exhibits different ‘errangenente of the | 


‘ 
Bi ate i. 


The funnels close the square bing; 
(cesess elevator) oe 


mast 


de The. lower portion 7 


ee ‘The . outlets are reseed at the sides. 


i 


Lees eiaiey section the. baron enshs ats poh a 
ed ribbed ceiling constracted with. the stiffening wall 
thereon. ‘Lhe elevator : rests’ on a brick substracture. — 
Fig. 507 shows. the treatment ‘of an ‘elevator ‘fo P gy 
the supporting framework. ‘is formed. by. thickening th Ss 
in Fig. 505 d. The elevator on the. whole consists of 8 ‘ete 
cells for a capacity of about. 4200 ini3, ah pt. . ee ae ar 
Kore “FOO s RAMS: On. the. meinforcenent By nis eevoror see 2 Py e eat ye ht 
‘glevators with ‘great bins are! employed . ees, aly ey A 
works or ‘industrial shops, ‘indeed chiefly. pee ei Of Conk, 


Pie ees Wate 
Biel a4 


lig dat 


‘411 , , fe 

The discharge ‘can .be properly soo arranged, that it occurs di- 
rectly before the retorts or boilers (Fig. 505). The side walls 
are mostly treated as retaining walls with buttresses. As an 
example of the reinforcenent reference ‘is made to Fig. DOG. 
For the bottom are. enployed ribbed slabs, o| ‘and these are ‘Supe 
‘ported by columns, that are best | meceived © ‘by continuous ‘found- 
ation slabs. (Fig. 512). To keep as much space free as possib- 
le, ‘itis advisable to use ‘spirally banded ‘columns. : Rie. Fas 

Note -2ep +2. Floors with rivs an. top hove the. savantoge, t ake as 
thot. the slavs at. the points | Of (uoxinun noments | (one of: thee Bae a aie 
Supports) “properly vie beneath, and. thor. the sbavs. one soctor ries by ae eae 
sonewhat mebicved by. the ribs, since. oe seuta WOSSes. mest che a) 
Vefly ow. the ribs. : oS ee, Fe ae 


Burther details are given by, the coms elevators" in Dankuars- Ca 
hausen represented ‘in Figs. 540, 5i, a ‘construction of Robert by been cate 
@rastorf & Ca, Hanover. | pip eee os e oe a ‘ ae 

In smelting works the ‘sowcalled sare: poakets play an ‘impor aS Bee ee 
part. According to Fig. 512 are provided four inclined bott et oe eee 
surfaces. ‘The cross walls. ‘support at ‘the middle a eo OE eS 


LOK 


track Saveude directly above ae cross. set sath cc 
Mote -Lep>202-. Buch an .eVevarton, 08, ‘shown - An PVGS. BLA, B18, 
‘As WUILA in excat numbers by Nayss & Breytag. So; also, Bee. ‘Wand 
buch ftir Bisenbotan. 2 nd edition. Vol. 12. 0. peg. | LE 
oo Allied to elevators are ore shoots, which serve to direct. ee en 
‘into the aifferent bins. the raw materials ‘coming ‘through a Bhs 
aft to the railway, thus. loading | directly ‘into. the railway. ‘cars | 
Standing heneath. Figs. 514, 515. shou a construction of Ro Gr- 
astorf & Ca, Hanover, ‘indeed with ‘fixed and movable ends. eye: i 
Section IV. Applications ‘in Hydraulic Engineering. — | 
Dams serve to raise the water level and.have the aim to obt- 
ain waterpower ‘for industrial works, or ‘irrigation of .a domain 
lying above the natural water level. bikewise dams are earieya 
ed for the canalization of rivers. 
As ‘for the construction in general, it is advisable te util- 
ize the pressure of the water -~ perpendicular to the resisting 
surface -- to “increase the stability of the structure. Large 
bodies brought by the water then cannot injure the crown as - 


Ore 


412 
readily. + é eit oes 
NOVS Le pe%®Ohe A vertical posirtion OF , the pressure | surface 

WOUNS require wars Strong SEV fenine to ‘Prevant & MOrVzontey 
dtsprlacenent Of. whe. DOW, Besides » Unjury. 40. the Crown my Note 
Vne shorp-ongbed bodtes ‘vs very WSU possible. ate 3 me 
By Pig. 516*is | evident the form of a dam in Theresa (ew Y- - 
ork). A reinforced concrete. slab 15 on thiek and i+: ie is. Wil) A vee 
supported by concrete piers: at distances of. 1.83, Ie gha crown eh ay tyke 
is Rai ae ibe a strong beam. For the piers was employed. 2) yi) iva” 
a mixture 11 3°26, and these are anchored to the rock Sd he) 
lts 3.2 :0om. Coa and 90 cm ‘long. Pi ae oy NG ge ae cite ‘ 
Fig 517 dives an example, .how an existing masonry dam ‘toy an TT eG 
increasing use of water way be raised ‘in a simple way and be us ei 
made ie oe iaakeo elt Son ae Laan} slabs a 


ym 


heated? below tne ordinary water evel ee i icilar apeningd, 
while Hap eet im bees bea ey crown are tie ok gh openings te 


oC a: 
better, so .entunely lose 


the sVob wel, ond. to: “ensue a be de the < hoon space 
Wwetecs bee whe Atwteton nt cee et 


here to aba guts” ie aie 

On turbine chambers, See -Pe a6 ea Be « 

Pacings of banks. are “to protect. the earth fron the strong o 
beat of the waves. Le ‘the use of ‘stone always: exists, the danger, 
that the ‘joints are. Washed out “in, time. Therefore ‘it is more ES oth m 
advantageous to employ continuous slabs of concrete or sof | CT ee 
foreed concrete, that are supported by driwen sheet PLblig Gee ONT ec a 
at least must be anchored, so that so undermining of the ORO ah 
ring ‘can ocour. Shore ‘protections on the sea Raturally ‘require = ae 
greater expense for construction and maintenance, than \protect— 
ion of the banks of cahals and rivers. A 

Fig. 519 illustrates ‘@ Shore protection according to the. ea 
ler system. A concrete slab strengthened by network : ‘reinforee- 


06 


i) 4 i . ' ¥. ri ‘ 
{ J i } 
¥ H , 3 —_—-*- 


ere 


ae 


# his 


fe 
iS 


rae 


‘113 : ae 
reinforcement ‘is ‘fixed to the ground by anchors ‘in the arth. : 
‘fhe anchors are ‘placed by first ‘berins a hole 4 :om Giameter w 
with a steel drill, then inserting a .rod and finally filling 
the .hole with cement mortar. The upper - end of the ‘rod is) ‘then. 
‘connected with the steel network. Division ‘joints at distances 
of 2.5 m:prevent the formation of cracks. 4 } e eu 2 

‘A ‘band protection -(in Stettin) ‘is composed of reinforced con- 
crete blocks set together, and . which ‘in.a given case may : -be : ro 
‘reset anea, ‘is .Bhoun ‘by Bigs. 520, 521. ‘The ‘joints are Lapp age 
cast with cement. (See B & B. A310. peidr)s a pe ks ; 
A sea protection of :reinforced concrete according to. tie ita i 
ralt system ‘is ‘represented ‘in Pig.) 522. Stepped beams have to 
gah. the covering ‘slabs and are ‘fastened | ‘by ground anchors — sah 
‘The slabs themselves may be souare; ‘in susller'\construsticns ane 
asin Fig. 523, and after the: ‘setbing. is ‘conpleted, may ‘be: fees) (5), 
tened by anchors with ‘conical » heads. oe Si aaer OA igi today, 
AOR bikewise for the regulation . of Trivers: anf in the construction 
of harbors and ship canals, reinforced concrete ; passes. ‘intoin- 
creasing importance. hocks, strengthening bottoms :of - ‘Trivers 
shore protections, moles, -auay walls, landing piers, dykes b 
breakwaters, lighthouses, etc., built of: ‘reinforced concrete, 
present manifold practical .and economical batt caus quay 
walls see ip. '470.° i i ee 4 ai ae ah ek 5 aN 
Big. 924 exhibits she ‘constuction of 8 ianotbetpien | where Ake em Ts 
certain groups of piles are connected by struts. ‘The piles oy hes 
and 3 mM apart and are reinforced by four ‘iron :rods. . (i 
Fig. 525 shows the foundations. Of a sea pier with: adouble ba, 
vow of piers of hollow ‘cylindrical section and enlarged seyhoagen aE) 
‘Bhese wells, ‘dL which have a diameter of 2.5 0 ond walls. 8 on 
thick are filled with’ ‘Sand and covered by a layer of. clay. ex’ f | 
ight of the well 8.75 m; distances between the wells lengthwise ae 
5 m, crosswise 6.5 mM. Cross beams » 30 om wide and: at least -1. 2n 4 
deep connect each pair of wells transversely and support a f1- nye 
oor slab 32 cm thick. ‘The facing at the land side is by a sheet. iat 
piling wall. At the sea side of the pier is provided a -protect- _ 
‘ing slab. 
An example of the ‘constrmation of quay walls by the use of 2 
floating blocks of reinforced ‘concrete, moved ‘into place by .a. 
Steamboat, sunk and then ‘filled with concrete or sand, ‘is. série 
ented in Pig. 526. 


NA 


£09 


‘414 , 
Recently reinforced concrete has also been utilized -for the 
construction of ‘pontoons and ships. ‘The advantases ‘it can offer 
are the followigg: — Strength, elasticity and ‘being watertight, 
no cost of maintenance’ and painting, durabidity, ‘no growth of 
plants and barnacles, smooth. exterior, built anywhere. Disad- 
vantagéous are the great weight and the areat draught required 
thereby. garger ships have double sides, 
Figs. 527, 528 show the longitudinal section and ‘plan of such 


a pontoon for a ri er bath in Nannhein. There are 7 watertight 


divisions, each witha manhole in the deck. Calculation. gave . 
across section of the pontoon with 1.5 m width at bottom, 1.55 
i aeebop, 1.27 m deep from the under side of bottom to. the \cro- 
wn of the somewhat arched deck. The thickness of the | ‘bottom, — 
Side and deck were taken at 4.5 cm. bength of. pontoon 10.3 Me. : 
Mixture of concrete -i cement +3 Rhine sand .+:3 pumice ‘gravel. 1 

NOLS Lepe209. Bor producing o wWOLSFTVSKY, “WSRRGL .and exter 
DOV Plastering was chosen an addition of | Cenesite, 10 pee at, 
ceresite veins added. to. the water for . Mixing. 


Z10 


OUR PTeveants any drip. ‘fron. Ane ‘ceibing, 


145 
section .V¥. Other Applications. 
@ Agricultural and Forestry Buildings. 

Buildings belonging here must first be fkreproof, since they 
are distant from other dwellings, so that assistance at the:r 
right time during a fire ‘is scarcely possible. ‘The ‘constructi- 
on of such buildings in reinforced ‘concrete proceeds rapidly, 
while bricks and split stone must often be brought several mi- 
lese Also the work of ‘maintenance ‘is only of the slightest «kind. 

Stables exhipit | mo rust -- and if porous materials are used 
for the cenerete -- also no sweating ‘of the walls, no ‘condens- 
ation of water for a low external temperature. Reinforced con- 


‘crete stables make possible the most careful cleanliness. For 


double :rows of stalls are omitted the. otherwise necessary col- | 


umns ‘in the middle passage, disturbing the passage and the work, — a 
If ‘insulating ceilings are employed (p. 19), the stable odor Cae 
does not penetrate into the attic, - and thus. does. not ieatpesy oe 


the ‘forage stored there. 2 


Note %oHe.%OWe. If. The :canstructioan - of ae hobvon cotting. tee Hh 
possitvrle, . than ts advisable. tmVae : coating zhe. Vompesd. eokling | em 
Wth. Tan, a Vayer of Aspharr - WnSUloting OUR, Or a) coor of. mel= 
ted aspharr - 1\2 om. thick, on. this bering FADGVVY | Raced a: ‘Vayer 
of ime cinder cancnete B.to 6-om. thick. “The. doupness .of. whe 


GORGKSLS -COnBROt HAss nto. the. cinder concrete on SCOURS | of. & 


the ANSUVarting Layer, Gnd AS & YOds conductor of abate Anis, ott 


a: Ttay , 


For barns, indeed both for new structures, as perk! as ee 


covering old open field. sheds, ‘the ‘reinforced concrete mode of 


construction is also well adapted. ae also ‘in most ‘regions at. 


Germany the cost of construction is somewhat more than for eo | 
ple wooden sheds, they are always cheaper than masonry and. eat ee 
timber structures, yet ‘presenting all the advantages of mason- 3 
vy ‘buildings. Masonry and half timber barns are also objected > 
to by many farmers on account of the particular disadvantages. 


of defective ventilation, or the drying of the sheaves hauled. 


in wet, which ‘is entirely obviated ‘by the thin walls, that: eS Rs 
mit sufficient circulation of air. Not to ‘be ‘forgotten | ‘is also 


the fact, that the barns are built fireproof and rapidly. Ins- 
urance premiums «for the building as tec 


are also accordingly iow. : 
Parm -houses ‘in the same kind of aeounseerian have ‘donne: ex- 


a 
a 


ay] 


rable, as well as manure pits, anit as well as tubs: for ge) Caen 
er and for plants. aa ras | eer eee 


eat extent. ‘They are ‘indeed heavy, “2 “bat do. not require ‘to be 


a movable fastening ‘for the: rails is senerally ‘quite difficult, 


is also less. Second, the stroke of the wheel is unimportant — 


116 


external walls with an insulating space 13 to 20 om thick, that 


remains hollow or may be filled with bad conductors of heat 1 
like ashes, peat, sawdust, ces Ny 

NOt]? Lops2id0. Sao De 5S. | | 

Likewise boundary and :frvit lattice walls are often built of 
reinforced conerete,. ‘fhey present the advantage, that the free 
walls between the piers allow the roots of the trees on the 1 
lattice to extend freely in all directions, thus making .possi- 


ble free passage ‘for the roots. Enclosure walls were previously 


descriped on p. 155, ‘Gheaper ‘is the» Use. cof posts with wheres: ‘Sy 
stretched between then. ‘Fhe posts are made ‘in factories, vamped 


‘in horizontal forms, and after sufficient hardening are set ‘in 


the ground. ‘The corner iposts are to be “age ine | both directi- — Gar eC aw ct 
ons h¥igs 5292 ee | ) ry SR te 
Fis. 530 exhibits the construction of a-vine one ‘in. reinfor- ie oa 
ced-concrete with a shaft 10 x -10 cm. The projecting abe Nate 3S 
a hook :for the stretched wire. For the case that the vine geet 
ws higher, there is opportunity to. screw on dsiperean 
Note Lepe®its See B& By 1942.0, BTL. ne te 
Feeding troughs: (Fig. 531) and watering troughs as well fe aN aR 
stalls and partition walls of reinforced concrete are most. ee Tt 


" Ue Oi 
u vt rey 


‘be. Street and Railway Construction, PN AEN a?) ca ORs ak ON 
Reinforced conerete ties have already been employed to. a rc aa ae 


moved much, since they can | ‘be made ab the place. of use. They 
are extremely stiff, durable, resist weather, are also cheap . 


in large quantities, and require neither plastering aes aaah an 


Sia 


of repairs. Indeed ‘it cannot be contested, that the making rm 


at the same time that ties of reinforced concrete Show less” at 


elasticity in use. | AR : | eo eG 


Note 2epe®il. On. the orther shand: the areot WLAN Anéubaten a 


On ’Wnoneanse Of - the ebobibiton OF the *troake ‘Bes of. meinforced | 


concrete olso. thus offord sveort seFBhy in use, An comparison 


WIR wooden Or: Lean. tVESs 


Reinforced concrete ties are to be Decdumended ‘hiset ec: ‘Sm- 
all ‘railways. First the dimensions are less, the weight of tie 


4 


iD conseguence 


of 


ran 


417 
of less velocity of travel, so that the disadvantage of less 
elesticity ‘just mentioned -rather disappears. 

The tie of byckerhoff & Widmann Co is represented ‘in Figs. 
5325 533, 534. It‘is 2.5 m long, 24 cm wide and 16 cm thick. . 
At the middle of the tie the section ‘islI= shaped, fo fasten - 
the rails serve creosoted wooden plugs ‘in form of a frustum of 
& pyramid, that by their sige allow no widening of the track. 

A spiral form of the plug has proved suitable. The kind of tie. 
represented in the Tiina ipahigns: ‘is calculated ‘for 3 :) aries: toad 
of 8 tonnes. | a Ny, 

Another kind of tie frequently employed ‘is the asbestos tie 
of R. Wolle Go; ‘in this the cement concrete at the ‘rail stg 

‘is replaced by asbestos concrete. et 

wurther see the Essay of Bre pastian, “wer Bxperiences with ae bl 
Reinforced Concrete Ties,” B & E. 1923. p. 78, 107. Vow 

A loading shed of factory made beams.(p. 28) ‘is shown. by Fg. 
535. The frames stand at. distances of 5-0 Be As tehbaape a a was” 
employed tamped asphalt slabs. Ve : | uaa 

The arrangement of cleaning pits (cleaning ¢ and examination 
pits) for car and locomotive sheds is evident from Pi8. 53052 h) 

_/ wfocording to Fig. 537 as in Fig. 536, ‘the rails rest ee NE 
of reinforced ‘concrete with connecting cross beams. ‘Their dis— 3 
tance apart lengthwise the -rails. is 1.90 Me ‘The ‘interval betw- aa 
een each pair of rails: ais. chere ‘covered ' ‘by an Seas reuovable i," 
planking. See B & E. L909 eps271. 


In bad ground is recommended a inlaieioran kG isn ae 


9 filling of the interior with earth (Fig. 538). ‘Cheaper age 

consequence of the simpler forms and ‘smaller quantity of steel : 

must be a construction with plain walls as “in Pig. BOA. Mrate4 a 
Gelegraph poles of wood suffer under the effect of the weath-_ ~ 

er and thus have a short life. In: ‘consequence of the dampness” 

of the earth the part ‘in the éround Tots, so that ‘finally. the 

entire remainder of the pole becomes. useless, even if the wood 

he still sound. sade ‘is. Te better to coat the SeeRS end. of 


large hole aad to attnne it by a aay of UES concrete. 3 
Still petter is the: ‘entire construction of the Bae: ‘in durable 
and weatherproof reinforced concrete... _ 

Fig. 539 shows the form of a telegraph pole ‘on the Wolle: sys- 
tem (Saxonia pole). The poles are generally made with rectangu- 


lar cross section. Lengthwise and crosswise is arranged a -rein- 


Ke 


Alt 


11h” 


‘ibits a construction in which the anchoring is) ‘in a mass 0! apt Tie 
Concrete: we behind the imal. This treats : where of Se ee 


ing, removal lot! pert of wall, -eted, anounted to. pW Bo 


‘£18 - 


reinforcement by round rods, while ‘in the saeueey zone are ap- 
enings, that not only denote a saving of material, -but also ‘c 
cause the pole to expose a smaller surface to the wind, and :f. 
‘finally makes it .possible to climb the pole without other aid. 


the masts are.eo set, that the greatest thickness lies -in the 
direction of the greatest stress. They are made in wooden or 


‘iron ‘forms, in a given case in the vicinity:of the .palce of use. 


Siegsart ‘(Zirich), as well.as the Schleuder Works + makes bh 
hollow poles ‘in factories. The working machines .permit. any) con- 


‘ical taper and any length. The thickness of the wall varies b ice ae 
between 2.5 and 5.0 cm. Gross section is annular. The ‘seinfor= a 
cement consists of either mild steel or cast’ steel. = fh 


Nove -LepeBide On BohLeuder concrete sae Pe BQ ve ae Cee 
A tight ._pole ‘in reinforced ‘concrete is: ‘illustrated ‘in, Figs 


540. * For later drawing ‘in the | electric. cable a gas pipe is. ise 
set in the longitudinal axis. -The poles: are dressed, ‘the. ‘bance ce 
hes being rubbed Level. end polisned. on top. ‘The: arms for ‘ORE ae 


arc lamps are made. of wrought ‘iron. Bi ch meth ete Re a 
Note VepeBid. Bor -Starvteo\ calucletien. see 8 me AQ42e ee ae 
gorbellings for widening streets ‘beyond - existing retaining Ae A 

walls are shown by Pigs. .541, 542. The first illustration meer 


Another widening of a street with an ‘important | projection of — 


5.6m, is represented in Fig. 5A2e AS a counterweight here nee a 
yes a reinforced concrete anchor slab, that. lies Bie Om below Ce aaa 
the surface of the street. | (Robert Franz Street in Helle-e-s). io . 


Deuts. Bauz. 1909. Gem. Supp. p. 94). Re ae i 
Curbs (stone borders) in reinforced concrete serve as ioe 

tutes for the more costly ‘granite curbs. Bor ‘protection against as 

driving serve ‘protecting steel shapes. Hollow blocks or those 


‘in ribbed form as ‘in Pigs. DA3, 544, have the ORTAR LORS of: easy 
‘removal and setting. 


Cs buildings for Sporting and Sbientific Purposes. 3 
Bis. 545 ‘shows the treatment of a curved wall with ancinded 


pokes for tea | oe “ | Agana 


HO 


SS 
ee 


he 


/6. 


Ly 


119 
stalls for wheels for the bicycle -racecourse ‘in Zurich. The s 
Slab is 6.0 cm thick. To connectethe slope with the horizontal 


Serves a cove at the bottom. In statical | respects one has to 


do with a triangular frame with a cantilever arm. + the ‘inclin- 


ation of the external slope is adapted to the most unfavorable 
resultant of the acting forces. In bad ground would naturally 
be required a tie-beam. The ‘full sunshine makes MGCERSETY the. 


arrangement of several expansion joints. ‘ 
Norte 1ep.216. On cabourtortions ‘See B & Be AQ43. Rede 


Likewise for the creation of artificial hills ‘in zoological — 


gardens is well suited-reinforeed concrete as shown in Fig. 5. 
546. The ‘illustration ‘represents. a frame for the bigers’ ‘den 


‘in the Budapest. Zoological Garden; 2 the corbei arm at the a 
right-is anchored is anchored in the: retaining \ dasaeet ! 


Rote 2.p.2i6. See B & Bs 1VAQ. pe2si. 


According to similar basal ‘ideas . may also. be constructed mon 


uments in reinforced concrete. (ysmortals). 
d. Chigney Construction. Nah age 
Chimneys of reinforced ,concrete : present many advantages: wor- 
thy of consideration over masonry chimneys. First is. that. the 


a eT eae 


dead weight is ‘substantially less, and also ae smaller. base ‘is . 
required. Wind end weather injure the exterior as little.as cae 


the ‘hot gasés do the ‘interior. Finally, also the durability of 
masonry Chimneys ‘is by far less, than that of ‘reinforced ‘conc~ 


rete chimneys, that represent elastic ‘beans : resisting ‘bending ee 
and fixed ‘in the earth. + No opening. of ‘joints occurs heres sB\ 
‘Bhe durability of the ‘chimney ° is also here: ensured, even ‘if. es 


the resultant of the dead weight and wind :pressure acts outside | 
a certain cross section. Fig. 547 shows the. appearance et ‘the 


recently erected chimney of a machine Shop ‘in Darmstadt. ‘The 


otherwise usual dimension of the shaft: ‘is omitted; “at 5s oO m 


SOT Sty 


Korte - Vepe®t Is See B & Be ABLS. Hp. 281. 

For greater heights ehimneys mostly have double walls and ic 
consist of two ‘concentric tubes of reinforced concrete. The _ 
outer tube bas to receive the wind ipressure and ‘is idcgh-emanehlk 


reinforced to correspond. ‘The inner tube dBi So constructe, re 


baby 


UBS 7 


height the shaf is heldb by the ceiling of the dollar’ dele as 
Mote 1spe21i. Bor Reinforced concrere | chimneys by. the weste= Bhan aa 

tance. %o vemarng | a f{iweford soferty agornsr “breaking “V3 eoetly 

Obtotneds for. ‘eigen ohimneys | One dickens WAS” si e's twofovda 


120 
to be able to expand under the effect of the hot gases. ‘indepen- 
dently of the outer tube. 2 | | 

NOC? -SepeZi7e By. the usually one-sided Antroduction of. the 
smoke gases is produced van MNEGUBL effect from Neat An. the wie 
Cini ty of - the Later ‘From. the -smaqke fWwes. A wniform HEOtUNE Of 
Lhe chimnsy wol\s occurs after. the. smoke gases have. taken .o | c 
‘CORBPaL upward wovenent, - ‘Therefore extending. the ° en Vining - 
beyoud a certain weltant Vs useless. 

The vertical steel rods, that <have to receive the boneshes' ag 
and bending stresses at the different sections, of the chimney Bron dyin 
are uniformly distributed ‘in the concrete-in the form of slen- Uae 
der rods, and are. enclosed | by horizontal rings at distances of 
about: = es Ca Vie ae 

« Mining Gonstruction. a ac Me ye re aeie Rn S  ahe die 

‘The avenge oft eeinforced concrete for Mining mpaten: and ee ee 
tunnels are. vapid construction, watertight (properties, good | ad- bays Sata RO 
erence to the rocks, ‘ereat resistance | with’ ‘sgall thickness. 2 
Besides the shaft structures also come mining Lae ube Loy: 
ground, such as cooling toners, hoisting. towers, Sige Rees 
es channels, ec ape a Fass ete as 


» - 
wr oe, 


The free space’ medigaaias ‘abe: rock | and ‘the. amet 
inferced concrete 10 om ‘thick is be sil with: ibaa eran VP 


a 


a 


£21 
Section VI. Examples of Calculation and Construction. 
Example ‘1. Calculation of : Hawag floor reinforced cross-wise, 
(See ip. -21). | 
MOte 2opse®iB. The calourlatron of .o ‘T\oor mMokatcrost. ‘crosswise 
‘S@ews vather Lengthy accoraind. to. the éiwen Buomple, yor Wa. 0 
PRACTICE one has Tables at .hand, from which he can read ainect- 
Wy how. the Voud 1s Bistributed in voth directions Ror Afferent 
‘proportvons of . the -voow, .s0. that. the- \weegae ee then becones 
substantially wore .simple,. Pas Any Niet yeaa 
Room 525 x 6.0m -- distance between supports 5-65 and 66 38 me hae 
hive load 250 :kil/m. : te 
Dead weight, assuming a:floor -18 cm thick. | | iif 
45:cm floor slab ? ene URED 50 


3 cm filling conerete iy — 66 kil 
Flooring mci ; A A es he “44: ‘kil 
Plastering : 20 kil. te 


In. Consequence of the» ‘crosswise reinforcement of the uae 
‘it forms a slab safe against bending ‘in. either direction. fom ie Le 
the load isddistributed “in both directions ‘is. establisned r ea: 
the equation -dér deflection ‘for each direction. ° ee Designating a ha 
the total load .per ut by p, the portion ‘falhing ‘in the direct. a 
‘ion a by .p,, and that falling in the direction bi BYP” ‘then 
With a uniform loading the following equations’ are obtained 


for deflection. is ale . : oe - 
Note. Bepe2iB. See Bort ee ew ea eat. “ 
. irection a:-- f = -a- x pedi SES Ms ag . 
' a OSE; eae Pee yoet: ‘ 
3 3 x aeese s/s PEE So Cae: Eee ak Ay 
Direction Re f= eas! Bybee Re a nS 
4/9 : 384 : aoe Bt ste, 2 | ie 5 a i : - BS. es » ne "tee Nie A I st My a sath At 
Bos -2— x 2 ce aes ee ‘Rp = PB. | - wed ee an 2 
5o4 BE ges BEM ae a ao 
: F 4 A ‘ x 64 a Wi aie i nak ie. ao BE Aa: kc 
Dee ee es ee 


pp = ((420 = 06586) =. 530: Oud x Pov eh ae 

The moment ‘for the main ‘reinforcement. ‘is thent—~_ a, MERC Ae RAN 
ea aes A ae 

M = 0.586. 2 x 530 = 425 000 om ‘Kil. es Ak aR 

If tao :rods oth diameter ‘of 12 mm are set-in each’ neb, “hen mS 


the steel section for. ‘1m width with blocks 25 om wide = 702 ont 


- e a ? 


’ 


) } ‘ 

ah aah 7 
? GY i 
m4 i; J 


ees es) 
Beer 


Rattaey * 
They ‘ 
a Roe 


A 


20 x T.42 ye 200 “x 46. S 


= SD ae ow a ne i = ou 2 
x 106 (4/1 t--= a8 = 7.48 ee 6.17 m 
. 125 000 7 ee 
dO, =- eee be WG.kil/om?, 
7.42 (16. 4- rot ) 
2°* 125 000 f 
oe Sen Re ie = 28.2 kil/on? 
4100 (68.47 EDR sh) =, eae) 
Z The moment of the other reinforcement -is:— 
ALO 6.132 


= 0.414 ae ‘x 580 = 105 000 cm kil. 


If in each joint be placed 1 rod 11 mm diameter and a rod 
12 wm diameter , the steel section for ie I Width amounts: to 6. 
6.89 cm?, 1.3 4 | 
bh-a=i18- 1.00 me hg zB ~ ye = 15. 2 CM. 


Then x ='5.7 om, o, = 1147 kil/cm?, Op = 27.7 \kil/om?,. 

ixample Z. Galoutation for Window bintel. Bale 
Floor i2 cm thick at the middle and 15 om at the wall, oe 
Load on Lintel py floor = 1800 kil/m ‘ ' Pe sits 
Clear span =1.90 m and 2.10, averaging SO Me 


—_ : has 
Distance between ‘pupports l= 8. “@ Nn . = 2,029 My 

Wall masonry = 1.0 x 0.90 -x 0.51 x eee | 736 kil/m 

Bead weight of lintel, estimated = — ey. ABB: 

Load of €loor on lintel = — os eee bite 
2940 x 2.252 Bein ow BO ee 
= s=——-aaana= x 100 = apout 18 600 cu AS a a oe 

The chosen section ‘is evident, ‘in Big. . 550. | hes 
Width for @aloulation =bs=—- + 28 about 60 cm. — 

AQ + 82 : 
Depth for calculation h -as = (=a = 37 -ch = 3) 34 on. 


Selected are 4 rods of 12 mm each = 4.52 cm?. 
Example 38. Calculation of. Footing of Pier. bigs: ‘Ds 61). 
The axially acting compression P = 50 000 kil (including dead 
load). The ground can only be loaded with 2.5 kil/cm?, so that:g, 


80 _000 = about 150 x 150 om. 
50 000 
Oe dk cee em ; = 
) 703 208 kil/con?. 


Fixing moment for b = 1.0 w. 


a B.e * x 60? -x 1 O° 


= 3960 m kil. 


ARI o, _ 1060 


M 
For Se, “> » b= a = 0.490 JM = about ne Cll. 
b= 80 + 3 = 33 cn: f, = 0.228 /M = 14.36 om?, 
Thus for a width of 1.5m = 1.5-* 14.36 = 21.54 om® = 15 rods 
of 14 mm diameter. 
The arrangement of the rods is evident from Figs. 551, 552. 
To prevent shearing the slab steel rods are also palced in the 
compresion zone. Footings of tamped concrete or of wasonry wor ‘ho 
uld naturally Nane substantially smaller values for. the sides 
of the base slab as well .as for Le 
Example 4, Calculation for a plat Foundation. (see p. 137). 
Let P be given at 80 tonnes per m in length and h = 100 on. ue a 
kA The chosen widths are shown in Fig. 553. — ca 


Load on Spenng oPBoS°28F4. nie welt gag Beet siggt ot? foundation 


= i OF mee ae as es a we. ase <i iatonp-catipaame au ati saan mnie 2 
Slap = a Toe doo Pe koe eee (1.4 kil/em®. 


Since the ground consists of dry sand the velue of 1.4 ee 
cu? is regarded as allowable. GE ete te < 
Bending moment at the middle of slap isco gone an Rais 


M = - 80 = 4.0 + 80-x 3.5 = ~ 40 m tonnes = 40 000 nh ml. Ce 


If a be made 3 3 Cm, then ‘is Hii = 200, 


oe 
1 r 4 * 

K = see 0,485 | ae ay 
ft. = about 0.230 x 200 = 46 cm? = 16 rods of 20 um. ee =. - 47, weer 
Bending moment under P Bysasi an fibres eee. at baghrote ON a ue 

M = : ae af os ‘e ‘x 0.40 = 95.43 li tonnes = 8 420° be 
i kil. 4 ‘ oF : yf, iy i D ; : hae a ae. d 
vu = 188.4, aT re darn yi | 
ft, = avout 0.215 ‘** 188.4 = 40.51 cm? = 13 rods of 20 nm ida 


i, = 40.82 cm?). | oan 
The arrangement of the rods can follow as ‘in Fig. 553. The 
calculation of the shear follows in the usual manner, as well 
as obtaining the actual stresses o, and o,. . 
Example 5. Calculation of self supporting Step. (p. 0). 
Clear width of stairs = 1.0 m. 
Rises’H = 19 cm, tread b = 25 cm. . 
hewn ae to p. 6 (Fig. 118) approximantely h = 49 = 2 % 27. 
42 Live load = 0.25 x 1.20:-x 400 = 120 kil. 
Dead load = 1.2 -x Os2e ; 


f ele 
pen? K\ 
1 bY \ 


ee 
hei 
Dh aed get 


thea 
ten vis 


ss ay 
ithyea. 


se 
ah pe 


wea 
Aah 
ae 


124 
Dead load = 1.2:-« 0.25 x 0.17 x 2400 = 128.0 kil. 


Plastering and wooden tread = FTO eS 
260 x 1.20 ere 260.0 kil. 
es cr eon = 156 m kil. 


Two concentrated loads have an unfavorable effect as in Fig. 
118 (p.60). | | 
Loading = aber 1 eight - + tread. and plastering = 140 ki. 
M = 140 * 4100 (0.70 + 1.20). = 274 iu kibs 
Chosen are 8 rods of 10 mm diameter. 
Example 6. Caloulation of Stairs with String. (p. 67) « 
for a given plan is to be designed a stairs in two fvights 
in reinforced concrete. The dimensions given in Fig. 555 are 
already fixed. Tae arrangement of the reinforcement beh cau ae gety 
to Fig. 130.in general. | 
1. Slab step. 
Let h = 10 cm, 2 = 1.5 em, then 1 = 1.55 mo. 


hive load = — | 500 wil/u? round area Hag 


Read load : biic hua bny’ step) = _400 ee Por ies 
a | “900 kil/ m? area. en 
psa x t,e01 Eb6 = 279 m kil. ace 


8 
10 - 1.5 
cal GRR Be? ene t = 2o09 
YM x : 
f, = apout 0.22" 16.7 = 3.67 ome 


Use 10 » rods of 7 mm diameter. 
2.String. pean. is 


the desired dimensions are evident ‘in atee 556. a = 2.0 ee 


ak: = 50 cm. | 7 ek es 

Step slab = 900 x 3.0x0.00= 216 ae 
Beam = (0.15 -« 0.10 -« 2800 ().8.0 =~ 108 kil. 
FEU Total emery te 2268 Kil. 


Ms ook «B64 36° a wile | 
The zero line evidently balls inthe cross section lof the slap. 


Then K = 20 — 2.0). = = 0.4386 :-.f, = want 0.26 Jhb. Db . 


5.36 om?, Use 4 rods of 1.3,cu. 
3.Landing slab. 
pet h = 10 om, a = 1.5 om, 1 = 1.90 nm. | 
Bive boad = bi 600 kil/m? on plan. © 
Gead load = 0.10 x 2400 = 240 ,, 


ith 


wi 


Wood floor = _& 
“B00 Kil/ wu? of pian. 
800 -x 2.0) -x 1.90 
Ms seedete te) Sats kil. 


bo 


= 0.486. :- Ee = 0.262 -x 19.5 = 5.1 on?. 
Tabborond take ve rods of 7 mm diameter. 
4, Landing beam. oe 
the deasred dimensions are evident in Fig. 557, a = 4 on, b 
db = aoa = about 6 cn. 


ou,  eunains slab with live load = 800-x 1-x 8 4 = 2720Ki1. 
Weight of peam (0. Ox 0.40 -x 2400) = SCC Rie 
jee haere ie Sa 4 Bs 
the 2570 | Total :  B600k. 
| p = ER = nas wan. | it a | 


oF 


rer — + 1185 = 2885 kil. 


= 2885 -x 190 = Fhe x ee ~ 1186 <x 48 = big 00 
- 148 Pe ~*20 ASO" =: 850 120°cm kil, | 


The zero line ries fais in the section of the rib. ‘Thea es ! 


approximately, f, = = 8. 54 om? Part qT, oe 


1000(46 — - 5). 
Take 4 rods of 1.7 en dieneter, = 
In this Example is merely given. the “process of ‘designing the 
work, The stresses actually occurring are obtained ‘in the well 
known manner, as well as. ‘the shear and bond stresses. din the t 
two beams. 
Bxample 7. Calculation of Sawtooth Shed. (De 199). 
A. Roof Slab. 
1. End panel. ee aed 
Dead weight = 0.12-~ 1.0 * 2400 = | “it 288 kia 


Snow, wind felt roof = ¥ aa FOO kids he 
Total, (say 450» ki). a i ” 


Span 1 = 4.0 nm. ‘ 
According to Kersten, Part I, 9 th edit. p. 328: - 
Muay = 0.08-« 450 x 4.02 = 576 ae ‘kil. 
Qs 12-cm: h- a = 10.5 om. 


ae, 2038 
tg yee | 


f, = 0.257 /576 = 6.16 om? = 8 rods of 10 mm diameter. 
i» Middle panel. We. 
Dead weight = 0.10 -x 1.0-x 2400 = 240 kil/m2 


Leaver 


oe * 


ante ; 
Sa sanl 
AS at: 


ae 


126 


Snow, wigd pressure ect. 160 kil/m? 
Total, g = 400 ,, 


Span lL = 4.0 m,. 
&. Moment at middle of panel. 
400 * 2,02 


+ binax = WERE Lr } = 267 m kil. 
ARG b= 10 omy h~ a = 6.5 cm. 


8.5 
as 3677 = 0. 52 


tf, = 0.218 /267 = 3.48 on? : s, it rods of 8 mm eke ten, f 
b. Moment at support. 
According to Kersten, Part I:< ch 7 
- Muay =~ 0-4 * 400-x 4.0? = - 640 m kil. 


By strengthening, h = 12 om: h midi = 10.5 om. 
10.5 | 
{= = 0.4 
18 0.415 2 hee 
F, = 0.274 (640 = 6.92 om? = 14 rods oe a mB dianoter. 


B. Beam of Roof. Shap. he AE aCe 


Span on inclined root surface = 6. “50 Me M take } 
Weight of roof slap = 400 -« 4 ARR IB 1s, BOD ‘ens neh 


Weight of beam = 0.25 x 0.20 x 2400 x 5.5 = 660 kil. 
, Mei Total ‘load Q = ae 8460. kik. 


Horizontal ‘span. l= 7.0 *« con® 30% = By 20 any us 3 lan fa 


For beam fixed at one side, } 
@ 1 9460 5.2 
M mas oi mm oR = 3515 1 Cat kil. 


G2. 
Compression breadth b &= === = as tae ee 


1000 
By Table for Y= beers i: Pesuten! ean 


, h = a = 0.0525 / 351 500 = 81.4 CMe 
i, = 0.0206 ¥ 351 500 = 11.3 om®. tact 
d = 0.0121 ¥ 361 500 = 7.2 cm (thus d = 10 om). | 
for h = 85 om, 0, = 20 om, f, = 4 rods of 20 mm, = 12.57 cm? 
fo receive the shears are to ‘be arranged corresponding stirrups. 
G. Stiffening Beans. ) ' 
Span 1 = 7.9 mn. 


4 


Dead load = 0.20 x 0.30 -x 7.0 -* 2400 = 1010 kil. 
five load: transmission 100 kil/m lin. = = 700 kil. 
998 | Qe | 1710 kil. 


Including fixing at one end:- 


ti 
Hirt 


Ba 


a 
PPR 


Kh 
a eg 


18% 


ae bd = 855, m kil. 
for b = 380 cn, a - — 8 = 67 cm, b = 2 om, K = ne = 0.415, 
5 a 5. 174/355 * 0.20 = ue cn, eee | 
Take 4 rods of 12 mm diameter, f, = TIO eae aay 


Yor the occurrence of negative moments at the fixed. ‘points 
proper calculations are to be made, + | 
Nore /-Aep 428s Lt would Le WetAer AG oVRowstKe ivpher tiene Tes 
extend entirely. through. | | 
D. Window Sill. es 
Span 1 = 4.0 a, wigs of skylight = 8 Ko) Bene a 
Dead weight = 0.20 -x 0.25 «x 4.0 -x 2400 = 480 kil. 
Window and sash 30 kil/m?-x 3.0 * 4.0 = BOO. a i 
Wiad pressure (perpendicular component of wind 
pressure on entire glass surface = 125 sin 60° x 1/2 | 
x 3.0-x 4.0 = Ba ie 2 Gb aia 


i hex’ 1480 kil. | 
490 x 4, cae, 
= 1490» Q = 426 a ‘Ril. 7A oes 
h = 26 om: h- a = 22 om: b = 20 om & = git. 


= 0.286/426 = 0.00 = 2.17 cu® = 8 rods of 10 om? ey 236 ont ear 


kelntopmement in the direction of the inclination of Moy 
the roof in consequence of wind pressure Uae oe ot to the 


glass surface). = BE5 gin & gO" 51. 5. x A; = 650 kil. ae met wh e ie & te a i 


M = eae 18518 a Kil. 


ue’ 


bh = 20 cm: b- say 17 cm: pb = 25 om: K = SB pro 
a = about 4 175/788: 5 0. 35 = ce 2 om?, = 2 swede lek 10° sng 


He pee Column. 
Loading, beam of roof slab, .P = 


sid = about 5000 kil. : 
‘Be. Ds s 


If the side = 20.cn, “Be f, = 20x 20 = 400 om?. 


=. = e j / 2. 
Sd) aside from steel 100 1s 5 kil/ om 


f, = 4 rods of 12 mm = 4.52 cm* = 1.18 p. reinforcement. 
No danger of buckling exists, since 20 > “i = 16.7 Gm. 
ft, Main Supports. 


Girder, roof slab and covering = 9460 kil. 
Stiffening beams = Pak 1710 kil. 


Re» ,) 
Seat sb 


Fae ai! 
‘ 


ty # Bran 


= 
oe 
i 


128 


Window sill, including window and sashes = 1490 kil. 
Weight of skylight column = 288 kil. 
Arches etc, = 652 kil 
Length of support 4.0 m. Ps 13 500 kid. 


Since for the easp ress section 20 -x 20. on, 18 times t+ 
this ‘is .exceeded by the height, __ the column must be examined SS 
for safety against ouckling. 
Greatest stress 6, in the cone 20 
b rele.so2 Bion. 


Then according to Rart I, £. = —-—- - = 9.85 ‘Kats saan 


e ina ee 
Take 4 rods of 18 mm diameter, f, = “90216 om* (2.5 p.c. teinf). 


Bands are to be pacade at bistances at least 30 cn. apart. 
Base of Support. 
13500 + 0.20% x 4.0 «x 2400 = about 13 900 kil 


For a stress in. oe phe masonry of 7 kil/tu?, the: ee 


aring area is F = ie about 2000 cm*?. 
Side b 09. #4 ae 
230 eb=/ =e 


Height of base h pes 


ti ‘Cl. 


h d of 2.5 2 es 
For a eresepe. 5B d e. grotn of rive, the side of the Rec 


footing is b fase = 6 on. 


Example 8. Calculation of an Arched Roof. eee 
Span of roof 1 = 15.0 m, a A oe: 
Rise of toot f= 3.0m 9) a a | 
Thickness dy. of vault at crown # 8.0 com: dp, = de cm aN sprin: ce 
ging: d, = 10 cm at distance — ,- a 


4 
Load per m? horigontal area, © le Sansa Rene 
Snow and wind = a Oe ROO eh 
Reinforced concrete vault aver. 10 To thick= 272 kil 
Plastering and extras = “i _ 28 kil 


Total 400 kil. 
1. Load uniformly distributed over entire vault. 
Q@ = dead load of one balf of vault. — 
S = distance of the same from Bar sayeree 
f = the rise. | 
Then the horizontal thrust of a Petri of vault'1 m wide ‘Ls: hes | 
Qs 2ng00--* RoR . 


pead load: Hy, = ar as Er long arags = £810 kil. 
ae 6 GSO LEA 
Live load: H, = ae eat a 940 sie 


Then the compressile stress at the crown is: 


‘iat 


129 


2+ A, _ 28 = 4,7 kil/om?. 


C4). F pereer = 
F 8 -x 100 
2. bive load extends from springing to crown. 
Live load p = 100 kil/m?. The maximum moment M occurring at 
the widdle of tne loaded half of the vault is:- 


p 1? _ 100 x 15° 


x 100 = 35 200 om kil. 


eee 
49 Axial pressure occurring there is:- 
Hy + sg 2810 a = $280 kil. 


Thickness d, of the vault there = 10 ca, ‘ fi 
Kifective thickness of the section = h - a = 8.65 om. 
Reinforcement by 10 rods of 7 wm with f, = 8.85 ens 
Distance of zero ec from m_top edge is:-— | i 
te * a * 3.85 {2 * 100 -« 8.65 
x= Lt fis es ee 4] = 2.64 cm. 


seiteselilt stress in concrete from pending:— AP ak ae 


OL. rr . : 


100 -« 2. 64 ( g. 85 - 


e 
z. oP = 34, 4 ton. | 


at 
oe 
R 


Add to this the axial compressive stress- 
3280 iat 
" 400 x 10 16 


= 3.28 kil/on?. De) ri 


Thus the total compressile stress = : B34. A 4 Se 28 = 37. 7 dI/on*. Py 2 


The tensile stress in steel from. Gasere isi- 
‘30 gag 


6 
ee ae 


1180 kil/ox? ah 


Total tension in steelin consequence of flexure isi- 
= 3.85 « 1180 = 4540 kil. a 
This is see py the normal compression ocourring in tne: i 
teasion zone by the amount:— 3.28 -x 100 (40 - 2.64) = ie 
The final tensile stress in the steel is consequently :- 


4540 - - 8410 
Tee 
3. Calculation of Ghannel Shapes. 
The maximum horizontal thrust per m length of roof is:- 
H, + H, = 2189 .#' 940 = 3750 kil. 
Since the chatheb’s extend over the points of support without 
abutting ‘joints, as the M,,, is assumed:# | 


= 555 kil/on®. 


ro 
PE dee 


can 
ty 


130 


p EF: BI60'-s) 4* 
hw nae 6 8 pee —— | OO = 500 000 om: keke 
12. 12 ; 
233 2 500 000 
4 “i500, = 5OO -am3:. 
fake 2N. Pp 22 channels with W.= 494 cm®.. 


4, Calculation of the Piex- rods. 
Tensile stress = 4-* 3750 = 15.00Q kil. | 
Require sectional area = B = 7500 = 12.5 cm®. 
Take 4 rods of 40 mm diameter with F = 12.0 cm®. 
Example 9, Caloulation of a Gircular Tank. ; | 
The tank represented in Figs. 566 to 568 in Potsdam (Goncrete 
and Monier Construction Co, Perlin) is circular in plan and i 
has a clear diameter of 9 m with wall 50 cm thick. Highest wa- 
ter level above pottom = 5.0 m. Height of outer wall above ‘pot- 


tow = 7.0 m. the too of the bottom lies 4.0 w below the A Lees ale 


line. 


The calculation of the ees es euauee of the wall. ‘is a8, follows. 


Tne borizontal water ‘pressure acting against the wall at ane 
upper suriace of pottom for - om? of wall. is te Hen ft 
p = 500 x0 001 Bs 5 kil/on?. LN | 
The tangential stress thus ae Bo, Bear ie eo 
ee bo Bote et 
Here r = radius to niddle of wale ee AI Cle 


Thus T, = 0,5 x 475 = 288 ‘kil. = ts tensile stress in 


the lekeu section of the wall 1 cm, high. ie 
h* 


The earth pressure acting externally = = sa 
for a natural slope of the earth at 37° and eo weight ¥ of nae 


sy near r 7 kil/ 32 a height 4 YS) Me ee BS 
therefore E = ~ 188 y = 3200 Kil. . hae 


ext ernal "Hloseare acting radially against ‘the wall at a 
ihe toy of the oottom for 1 cm? of wall is:- | 
= 100 x 0.0016 = 0.16 kil/cm?. eet 
The Ret sh stress tp) thus produced in the middle 3 the 
‘ail and acting on the lowest 1 cm? of the: section 1 cm high, . 
Tp * Bs? = 0116 « 465 = 76 kily om 
The vangential tensile stress is then reduced by this force | 
Tp, and thus amounts to 288 - 76 = 162 kil. ¢onsequently acts 
on the lowest strip of wall 0.5 m high 50 x 162 = 8100 kil. 3 
This tensile stress must be entirely received by the rein/- 
formement. According to the former regulations, the maximum 


allowaple tensile stress o~ was 4200 kil/om?.., thus the 


‘131 


required steel section is = f, = — = 6.75 cm®?, 
Use 6 rods of 12 mm diameter. According to the new 


Frussian Regulations (o, = 1000) 6 rods of 14 mm would be used. 
fhe tensile stresses diminish upward. Gorresponding to this 
reduction, the steel section is diminished upward. 
Example 10. @aloulation of a Water Tower. (p. 187). 
Figs. 569 to 572 exhibit the construction of a water tower 


erected by the contractor R. Richter, Dessau, to contain 120 | 


n?, + The piers with the mixture 1: 3 were tamped ‘in forms in — 
the usual way. The piers are carried down without ‘joints from | 
the wall to the middle of the foundations the foundation and | 
wall thereoyform an united whole. The most dangerous point is 
the ‘junction of the support with the wall, and was ensured by 
being stronsly rounded, The roof was of concrete in the usual | 


manner, furnisned with a ginc ventilating cap. Besides amanks 


hole was provided in.the roof, accesiple by iron pins set vie 
&@ pier. The entire internal surface of the tank was. covered — 
by a thick coating of cement mixed 4 2 1. Other insulation was 


not provided at first. But the addition of an external insules 


tion was made possible by corresponding projections | and by the 


insertion of pins. The tank was built within 6 weeks, and thes 
rewith was commenced. the construction of the pipes, Lae oie 


ugh the ground terminated in the’ tank upward. | : 
Norte 1. PoAB5-. The entire Structure wos. constructed vy. ‘the 


Gheapest means for a factory, ONG . asturally mepresents only oO | 
Hun|ely UtIVitorrvan wouriLaind, and spectol ovchitectursy. treat nie 
Ment Lens owMLtted from. the first. ig Rea PAL Se 


The statical caleulations for this water tower were ade as ae 
follows. ‘ . 

1. Bottom Slab of. the Tank. aac 

The pottom slap of the tank has an average span ‘of 8. 15 Wr hie 
and is fixed to poth the beams as well os ie) the beam under a Ne : 
the wall. ; ! 
Bead weight, 1.0 x 0.25 -« 2400 = “a oo ‘kil. 


Water pressure, 1.0 x 3.6-x 1000 = , 8600 kil. 


| Totalom..ce 5 eee and 
= eee = 3470 m kil. ” 


h- a = 0.39 /3470 = 238.0 cm: bh = 25 cm, Papi 
f, = 0.298/3470 = 17.3 om*, ; + tg 
Use 10 rods of 15 m. bat . 


23g 


132 


The shear at the beam amounts to V. = eh Aba = 6615 kil. 
6615 100 -x 3.38 

Same ee ee ae eee = ; rf j 2s. Se eres ee ae e 2 

bagasse Sia kilfeu*s it, Ox ai = 7,0 kilfon®, 


This value for.t, is so far permissible, since on the one 
hand the steel py pending presents a substantialgyy higher res: 
‘istance to peing torn apart for the concrete, and on the other 
the calculated maximum shear V- = 6615 kil ocours directly at 
the support. Here the section is increased to 40 cm high 7 r 
rounding Beis‘ corn@r inside, Sig Clare 


= = 2. 5 inegrgnes = 2 
Te 160 * eae 18 kilfcnt: 4, ’: TCE: or 8.8 kil/cm?. 


The bottom is supported by beans, that: transfer the loads to 
the piers. The beams are taken in the calculations as T+beams 
with free supports. The increased depth resulting from this - ‘in 
creases the safety of the siructiure. | | 
The free length of the beams incl ydine support: is 3.0 ily the 
mrsee width of the bottom slab ~-- = 1 He 


= 4200 -x 3.15 = ey pike 2380 kil. 
a weight = 0.28°* 0.38 -* 2400 = Me 202 kik. 
Total: = 9 » 57 230 kil. 
The zero line falls in the slab (for 1 m width OF) slab) . 
2 ‘ : 
oo 450 _ 15 110 m kil. 


wip 99 J AEDIIO = 4o0men eee cures Kobe ee 
f, = 0.298 ¥ 15 110 = 36 om? = 8 pods: of 24 mm, 
The maximum shear at the support = 13 430 “x = 20 115 kilo 
_ At the support (a - a) = 7 cm: then the shear ‘in the: concrete 
20 115 ee Te ga keg 
100 -x ey 
Although the shear remains within the dlowaple , Limit, a ann 
are pent upward. For the rods extending below. the bond stress” 
is»~computed at: a 20 145 ie 
at Qe 7 Bae 67 | 
Substitute rods for the bent ones are inserted, and there 


results then : a i 20. 4165 ees 
Ps Be aoe ee OF 


h=a 


3.0 Kil/ ont, 


Te! = 


im 6.6 Kil/om® ° 


= 4,96 ki Vjen® 


2. The Wall. 
The wall is to be regarded as 4 eauwkasten ‘gkxea at the ba fade. 


fae waximun water progeure on a strip i w wide of the wall 
surface is ‘= --- — x {000 = RROD kin 
And it-is applied at a point cE = 1.2 mw from the top of t 


rt 


fe : , 


234 


240 


133 
or the bottom of tank. | 
The dead weight of the wall is favorable to the calculation, 


but on account of safety, is omitted in determining the moment. 


Maximum fixing mowent M = 6500-x 1.2 = 7300 m kil, 
h- a = 0.89 / 7800 = 34.4 om: h = 36 cm. 
£, £ 0.293 / 7800 = 26 cm?: = 13 rods of 16 mm, 
At its junction with the bottom the wall is strongly rounded 


inside, so. that the formation of all cracks at this dangerous _ 


point may be avoided. 


The wall is thinner upwardsa at 1.2 m from the bottom the m 


e- 4 3 
moment is = KM = telbdl 1000 0.8 = 2300 m kil. 
h = .a =.0,88'/ 2300) = "18.7: bh =720 om 


ff, = 0.293 if (2300)244.06'en7: a37 rods of 16 Til 
At 2.0 ii a the top edge the nonent ‘1si- | 
28 -* 2,0" 
M = saa agen 1000. x 0.67 = 1340 m kil. 
bh ~ a = 0.39 ¥ 1840 = 14.3 oat b= 16 om. 
ff. = 0. 293 / 1840 = 10.7 om? = 6) rods of 16 I» 
Ad 0 m from top ode ‘the nomen’ is:- | | 
Ms a «1000 * 0, 33 = wins) 
ha = 0.39 7 165 = 6.0: ne Bom. SNe 
f, = 0. 298 / 165.=)2. 76 cH 6 rods of 18 am. ea 


For ae distripution of the acting forces as well as. to ee 
recelve the considerable stresses ‘an the tank, that arise in ve 


filling and emptying, horizontal rings must be inserted. 


On account of greater safety the entire water ean is ie 


assigned to the rings. ‘hele i000 3. 3.62 


h 
The required section is then + aid ae yD x gi 2 = 


ameter, that are firmly hooked together BY the” ‘joints. — 
3. The Roof. : | | 


Norte 1. Ps240. -‘Dhe cotcurlartion Vs -anby | hosing “opproxinotes : Deke is | 


‘VS CONGETUS a Conical Yoof, which Vs also to be computed 08 such. 


The roof surface forms a coné with inclination = 20°. 
The load on 1 mw width at bottom edge is :- 


p a * BBO =, 680 Wiy, 
2 nee Go eae 
: i2 ‘ewe BY 


8 on?. 


Wor this in the lower weter are placed 10 rings” cot’ 16 mu rh Cr oe 


Ly 


134 | 
h- a= 0.39 / 189 = 5.34 cm: h = 8.0 cm. 
f, = 0.293 / 189 = 4.08 cm? = 10 rods of 8 mm. 
Distriputing rings of 5 mm diameter are placed at each 20 cm. 
Tae horizontal thrust of the roof is H fis G00 &% COS a. 


A uf 
H = 3 6380 = 0.84 * 0,94 = 99 kil/m lineal, : 
fo receive this thrust is required a thickening of the top 
give of the wall. | May 
i ‘ Bay Ps Bek ae ge | 
fae free leagth of the ring between tie ads Aart = 5.35 m. 


fe 
te ee a kat 


The pert of the wall A ea amounts to Sa = 0.90 » for i, 
an essumed ratio of stresses y = “307 te ye Sth : 
/.355 
h- a= 0. 43 Ce = | | 
= 0,228 /¥ 355 * 0,9 = 4.7 om?: = 3 Sodiiee 15 mm. 
fo anchor sa tank at the top edge Pp’ tie rods, each of 20 um 
diameter are placed in the upper ring with @ plate for distrip- 
uting the pressure. at the top ocau, ‘since the wall is -Pegarded 
as Tixed to the bottom. — 7 guns Rae eg a ea Uae Ns 
4, The Piers. Aye Ror a an y 


10.9 cme: b = ds Che: 


The beam calculated vader 1 gives a ‘load | on te: piers. of ab ius 


out 20 000 kil. It is therefore assumed, that. all five piers 
are equally loaded. By. this assumption ‘the beau. serves as a -) 
plate for the piers. . | Re } UB SM ae a) 


The. total load on one | pier neue to 
120 000 


later pressure = 


5.4? x Kx OGRE 


i 5 
faa 
= 
ie 
ft 


eg elo 4 360 
ne -* 042% 2400 | 


Wall oN a aac Q 200 a : : : ck ia q ai e 


4 ae b 
Beam = 0,65 Sete As x 2400 : - 250 
Girt = 0.65 x se oa 2400 = 1 230 
Pier = 12.0 -* 0.65° x 2400 = uo : 12 100 
Roof load = 6.3% — x68 = 3.360 
Roundide angles inside = aN debat 
Total, about - BB 000 kil. 
‘For .a rigiasmpgenen t feo = 4 rods of 16 mm = 8.04 cm?. 
5 


ne sae. a fee 24 000 kL - ne ne ek: 


135 
fead of one pier on ground is 55 000 kil. vit 
3 000 Y 5 


Weight of footing = 1.07 -x 1.5-x 2000 = 
= 2.0? »: * 0.5 -x 2000 = 4 000 
go akal @ Ba ROOMY S 5 peg 
’ works Gedatn @f 2.0 m for footing: fe oa ee we ‘ 
|. 62 000 


7 2 
Oy = OD Doe = 4 55 kil/on?. 


The girst at a height of 6 m are arranged to wetios ber Ae os 
the supports, yet the piers are made safe noe their entire len 4 | 
sth against buckling, ; as / Pde a 

For practical reasons the Bess are given ae” sale ‘ulate a 
as the columns.(or piers}. x 

AYA ss Example 11. Calculation of an Angle Reeining Wall. (p-164). 

The selected dimensions are shown in Fig. O78, Tae mass of 
earth and the back of the wall are both vertical. The ios of 
the front and back footing slab are sa at distances: ‘of 26° 
Ww and are 20 cm thick. : ? ! ML a 

Neglecting the rios, the davestigation is as follows. ces 


0.10.4 O42 
Weight I = t= Le * 4.26 x 2400 = 534 AG dg 
Weight IT = 0.24% 2.0 x 2400-2 see bn oe f 
eight Tit = 1.8°x 4,26-x 1600 = A a ie aa 8 860 Bo se iy 


‘Total: vertical load 4064 548 ‘kil 
Wor caluclating the horizontal resultant of the earth press 
ure the friction petween wall surface and filling is nealegion 
and it is assumed, that the plane Cee coincides with» 
the natural angle . sc a (here 45°). ie Seatac ees 


rr Ary 


B00 -x 4,26 * Hees 
k= : SbF tant ==) = 1600 Ae x 0. 172 = - 2810 oe 
Then is A di 546 = 1534 -x 0.62 + rises 3 “x 1.0 4 + + 8860. “x 4, 35. 

v= 1.22 mM. 
wx Ab (646. 4:11 B46e% 1.22 ee BID x iL, 66 = a 
w= 0.82 nn. 


The point of application of the total eebiane R secordingly. 
lies within the i and the eccentricity is then:- 
= 100 - 82 = 18 om. 

Maximum pressure on graund . ae 5G a of footing: - 


_ 11.546 
(AES mee Oy oe eter — e 8 2 
Mana a0 £1 + == = 0.88 kil/on?, 


This value corres@onds to the allowable pressure on a soft 
clay ground or a very wet fine-grained sand. If a better grou 
nd exists, then one lessens the breadth of the footing. Weight 


Ber itsNs 
Bere Su 


136 : . 
ITI .then becomes smaller and lies more toward the left, so the 
at the eccentricity is greater. 
LAY Example 12. Construction ofa Haal in single aisle with G 
Gallery. 

Frane trusses-for the left side structure of the Goncrete H 
pall at the Beipzig Technical Building Exhibition of 19138. Er 
ected oy Rud. Wolle Go, Leipzig. 

Fig. 574 shows the steel details as well as a section through 
the frame. 

Fig. 578 is the treatment of the roof surface. Distance pet— 
ween trusses 4.7 m. 


AAG 


in 
ee oe 


aN 
‘ * 
ie 
ha ee 


Ladin’ 


437 | / 
Séotiow VII. Designing, Calculation of Quantities a 
and Gost of ea Workshop Floor with Girdess and Piers. 
In the following will be calculated and dimensioned a floor, 


cansisting of floor slap, Girders, beams and supports. Determ rae xs 
inative for the calculations are ‘the Prussian Regulations of A 4 % .e ewe 
1907. On account of the. continuity of the floor ‘aa and vedas faut a Ye 


wili pe employed for calculating the bending nonents, ‘the Tat - 


Le piven in the Appendix to Part I, 9 th edition. At. the ‘end: a * a 
of the calculation foklows a graphical representation of. the ae Vous a 


floor as designed with girders and Piers, with the required — i aalghith REEMP AS ee 
steel reinforcements, as well as a caloulation of the quanta 9 ep: 
ties , prices,and form of bid. pen Sir | AOE Sih FR ai pert j 
Be Caloulation of Floor Slap. : | ene Ey We ct ae 
The floor slab. ‘is regarded as a continuous. dean on "6 supp- pe CN ee lee 
pg Orta yet according to the official regulations, this ebomnedtert a fr ae eth 


ion can pe extended only over 8 penels at neat, + Spans: between mae % 
the different supports aes 2.5 m. my. | ees , 
hive load = , e. = . 500 iU/a* - sree 


Dead load (60 SN 1. ae = 250. eR, 

te . —— ae Sa 

HNOte Le Pe 245. Bor structure) members: exposed. ie ‘tron ee 
ocks or variations in Loading, . the Woe Voaa. » ‘Ancneased by SO. 
‘Ber Gent Ls. %o be employed in the | eovoulotionss | i et 


Phas tak" oak? 


| | | Total = 750 ki m2. ee reer a 
Assumed for the end panel at— i? es Bef Ree anne 
Dead load of floor 12 cm thick = 3 B.A: Ee ee ARO i 
For plaster and flooring 4 cm thick = ne, Oe ten 4 
Assumed for inside panels b: oe A eS a at a Wea Se 
Dead oad-of floor 10 om thick = = 40 eil/m®, 


For plaster and flooring 4.cm ‘thick = ee aa on: Pe taie Oe i 

ne Phy RAC? SAE Reka EOE GANS a coe ae 

The pending moments are:- RE See To Et Cie AI ACAD ir 

Bnd panel a: M g, = 0.08 x 888-x 2,502 =.+ 194. ae he 

Mp = 0.10-x 750 x 2.502 = + 469° 

<a aay 7 7 + 688 

Inside panel b:M g, 3 = 0.025 -x3840 -x 2.502 = + 53. 

Mops 0.075 ‘* 950 -x 2,50? Bis 352 

246 ~& pax = ie ee 
Middle pier (side pre Now 

“Mg, = -0.100 -x 388 -x 2,608= — 243 m kil. 

—M.p = ~a1167 -* 750 -« 2,50°= ~ 546 m kil. 


x x * 
it | Mae 


BB SE EE eB 
5 5 by ase nak Me 
ad 
ke 
. 


4 ae i 


Ni’ uae 


138 
Determination of thickness of floor and the reinforcement. . 
Assumed is a crushing resistange of 240 kil/om? for: ‘concrete. 
The allowable stresses for conérete are then for sikfold safe> J 


ty: Op, = 40 kil/om?, and for steel Oe = 1000 kil/om?, 4 

End panel a: moment in panel = + 663 m2 kil. | 4 : 

for a aii: Sp = 188 ‘il/on? and GO, = 1000 kil/em? are compu re ee, 
ted:—= : ; 


F Bs 0.406 / 663 = 10.5) CM,’ 
A + 4 = 10.5. + 1.5 = 12.0 om. ee An Gi ol 
Fe = 0.280 / 663 = °7 32 on? = - 12 rods of 9 mm, with f, e = 7-63 on®, ree 
Inside panel b: moment in panel = + 405 m kil, | 
For stress 6, = 36 kil/cm? and o, = 1000. kil/cm?:—— 
h = a = 0.423 / 405 = 2.5 on, 
} ‘b= 8,514 1.5 ids on. a Ge 
= 0.267 / 405 = 5.37 om?, 9-rods of 9 mm, with fe =).0.72. em, 
pon support: (side beans): moment. at support =-— 789 m kil. 
Byrthe arrangement of arches h is. increased +020 50my a 
for stresses 6) = 21 kil/om? and » a, = 1000. kil/on?:— 
h- a= 0.659 / ies 18.5 cm: h = 18, 6 ot EIB. 20 om). 
= 0.166 / 789 = 4.66 enue. AN aes a: 
‘By the bent rods a the Jame: floor slap fe is. "abundantly 
provided for. Bay eh Ny 
b. Calaulation of Side Beams. . . ) he 
The peams are tobe regerded as. Reslintaus beams. over (4 p supsto. 
Span 1 = 6.0 m.: width B of. load = eeb0' hh. 


eA? Loading by Live load and pea =p = 760 - oe 2. 5 ‘ 1875 w/a, kita 


Loading py floor panel a, 389 -x =<s = 2 fk as 485 Liner 
Loading by floor panel b, 340 x Le AN Saray aes 05) a ARB cies 3 
Toading by mete y of beam (estimeted)O, 25 -x 0, ) 45 *2400270. ees 

Ne NS 
The pending nonents areim— § ve SNe 
Bnd panel Ia, My = 0.08 x 1180-x 6.00? = 3400 m kil, 
My = 0.10 -x 1875 x 6.007 = 6750 a LG ea 


n kil... 


jxackexpanek 5X: . RR kiG IO RubenkxexAH 0 kil, 
Widdle panel, Ip, Ms; = 0.025 -x 1180-x 6,00? = 1060 m kil. 
lip = 0.075 + 1875 x 6.00? = _ 5060 m kil. 
| Mo max = : 6120 m kil. 
Middle support: - Wl; = -0.100 = 1180 -x 6,00 =- 4250 m kil. 
— M) = ~.1107 -x 1875 -x 6,00= - 7870 m kil. 


Myce = Big A oe 


: : ) i 
ae _ 2 


DR 
Akos 8 


ae 2 
Anka, SR MV 


139 

Determination of Bead Section and Reinforcement. 

4s limiting values of the allowable stresses are also here 
Sy = 40 kil/om? and o, = 1000 kil/cm*. The loaded width » can. 
be assumed at 1/8 py she. poceerae Regulations. Yet to work moree 
advantageously, it is advisable to assume b = h up to 2 h, by 
which the section of the concrete is indeed ‘increased, but the 
steel section is censideraply reduced. 

End panel Ia: end panel poment = + 10 i150 kids 

for stresses of o) = 40 kil/em® and o, = 1000 kil/an*, and 
@ compression ‘me fp=2 Di- 7 


:50 ae 
A beg ° = 4 = 4 6 + wb H4 Ril 
h a = 0.39 A 5750 4055 ion 2: hk) = ae 3 5 . 4 Soe 
'e = 0.298 ¥ 10150 = 28.0 one, 7 rods of 23 mm, f, = 28 em? + 
bah Le P+ 24¥e Tf W be aseumed = 2% BO\S = 2.0m, then, 


/ 10150 fone yh 
oe fi > PaA®) = 27.8 ows WW = 2768 + 462 = 32.0 OMe 


fo = 00293 #10150 * 2.0 =-44.8 ont, hk 
Aye Middle panel I b. Panel moment = + 6120 m kil, fs Bsa 
The height bh of the beam remanis the sane as for the end parte Bs 
nel. Since the moment M ‘is now considerably sualler, the stress 
in the conerete must be reduced. i 


Wor stresses of 0) = 29 kil/cm? ‘and Ge “ot an Se 
&@ compression width of b «(2h = 0.490 Wi ts ier ee ae Bs i 
bh- 2 SS = 41.5 come: hs at. 5 + a. 5 3 45.0. som we ed 


= 0, 221 ¥ 6120 -x 0.90 = 16.4 on: 4 ‘rods of 23 tio gee oy , 


aoke Neps2hBs Assuming ’ = 2 ,0\6 * Re Sent it 


A 1.0 = tote = 27.9) Cm .t bh = 28. + 4, ae 92. 20 om. . 
Ko = 06224 /G120 -« 2,0 = hed on? a ne a a Fi INE 


aq7 Middle pier (main girder) % Moment ad) support. eat 12120 u kn. iis ae, 
by the arrangement of arches h‘is ‘increased to. 45.0. + 20.0 
= 65.0 cm. As. compression width bis. taken the width 2 Da of the 
side beam = 0.25 mu. | et Se ar 
Por stresses 6, = 50 kif om? and Fe = 1000 Kil on? 


x= x 0,59 = iy. 2D Me. 


1 + 5 “x 50 . 

= 12.12 ~ 5 * 0.25 0.26 x 60 (0.59 ~ 0.088) = 4.20 w tonnes. 
1000 (' 0.59 - 0.25) it 

1000 (0.25 = 0.06) (0.59 — 0.06). 


Lip => 4.2 ~* ‘ad 14.15 om? 


Nn 


- 140 . 
Bent upward are 4 rods of 23 mm diameter with ff = 16.62 om*, 
~ 2000 - “*.05 250 » 25 +%50 1000 -x 4.2 

e seen. ~ 1000(0-59 = 0.66). 
Beat upward are 6 rods of 23 mm with f, 4 24.98 om, 

The shear in the conerete ‘is caloulatea at the ike of +t 
the end panel Ia as follows:- 

Distance to zero line x = 0.875 -x 41.5 = 16.6 Cl. 


f = 23.55 cm*, 


+ 15.6 
Bo ee 
h-a Be 41.5 - 5.9 = 36.3 on. uM 
Y, 9165 uot 
= ae a = cE. WIS 
a SE oe 8 a yee 
b,(h- ae 3 ey, | 


The shear exceeding Me Limiting eas of 4.5 kil/on? must be 


received py bent rods. 
To ae) 4.5 1 1 vet — 4.5 ee oe) 
xX. = one ee een es 


To: 2 ‘ ge s ry) Rit ‘ 
Steel section to be bent ‘is:- ; 


6 es 


£§ = 3.5 ¢ bg(t): - 4.5). = Sib x to 66 x 0.25 -x iSo6 ig a is cu ee 


2 rods of 23 mm are pent, with Fae) = 8.80 ome es a by ot he 


Besides also a corresponding number of stirrups are arranged en oe i 
The bond stress between concrete and steel is computed. fo h 


free sli of the end panel Ta with o rods lying at bottom:~ 


7.0 kilfeon®. pee 


Ts 


Sth -a- - 3). 


In consequence of. ne high kona stress. a strong developuent eR hes | 


of the end hooks is recommended. | ae 
Yote 1. .p.249, If for arches eee. eons a Sa: dev apesaen f 


SO, . then. the Vniting value of Op = BQ kil/on? may ee consia- 


220 ,AVLOWGOLE.» ‘the new Bakee Taneayet ere Ln. Snis case even aa Nic ah 


40 Op = 70 kil/on8. 


Note 1. po250, Bais can be considered allonablee - “Phe » sides | 


Brvactples” of . the Gernan. Goncrerte Tnrian OVVow at Vwi t ving BATESS 
OF “Ted kil/ cm? .the ‘ Nuptinaedpopete hts azar see: Mek lee: The bond 


Stresse 


The side beam I' is vee loaded by the floor 40 om behouk i 


Yet since ‘its M max are not essentially smaller, ‘it receives. 


the same reinforcement as for the same conerete section. 
c. CGaloulation of the Main Bean. (Beam Tr) 


bee 


141 
¢. Calculation of the Main Girder. (Beam IT}. 
The beams are to be regarded as continuous over 3 supports, 
&@ single load acting at the middle of cach panel. Span 1 = 5 un. 


RG 


Dead load from side beam, 1180 -x 6.00 = ‘7080 kil. 
bive load from side beam, 1875 « 6.00 = 11250 kil. 
| | cay eee 18390 kil. 
Loading by own weight,(estimated) = | 
q = 0.35 x 0.70 -« 2400 = 590 kil/m. 


Load on the Suppor Las | 
A208 =iNay = ag ++ 590 - oh DS 50. = 10640 kil. Sekt et ot 
yoment in panéel= :- oe . eg 
Pol’ qe 18330 ..590-x 5.0 Tha 
Mnax = (=r , “ath = oe a BCR dees cee 24750 it kid 
On ree at ‘Of, thy continuity of the girder, Muax: is) reduced — 
to. +M= = Mou =—- -x 24750 = 19800 m kil. 


5 
For stresses of 0, = a7 xilfou® and ¢, = 1000 kii/om?, aa” 
& compression breadth pb = 2heal. a0 mare. gomputed: i Sale if 
§ /19800 ‘, ge oi st 
“h-a = 0, ed é 4.40 = 63.5 cm: h = 63. 5 + 8.5 = ayo oe 


= 0.207 / isa 84a40' > 34:6fem* 6 Pode of 87, ‘na, eee = BA. Ns 


"pysteagas to zero line me O04 288 sx Vicks ae Ome oe 
Shear in concrete at the support A isi- - so hits a 
V- max AnGte 3 ny 


wha Peo. 


Since the Limiting value of 4.5 wilfoa®: is edidzetoa) “the” she 


ears must pe received by bends upwards in ods. {ONS AE Cau Racer ata 


on Bee wep 5 O28 eta a ! = 0. 28 a 
To: “heures See A 
Pe ais section of rods to be: pent up is: pace: 
= (355 -.6° bolle! - 415). = 3.5.4" Q. 33 -x 0.36(5 « ah 4.5) = ays 37. ot 
i rod of 27 mm wita Ef: = 2 73 cm? is bent upward, and furs 
_ ther a corresponding nunber of stirrups is-arranged. — a 
WR The bond stress at the support A with 5. vods. at the bottom ‘is? 
Vo max =) Um _ 10640 


Es = s en ee ee 
ieee: Oe) ae 


In consequence of the high bond stress strong hooks are . pro 
vided there. 3 
Mohent at Support. 


oe 
Hives, ae 


a ry 4 kil/ ou? 


\ | 


142 : 
Tne moment at support = —- Wi = panel moment at middle of free— 
ly supported beam. | 


Ei, gi?_ (1888 | 590 x x 5.0 
7M Me Bike t cee om (gee i —=) * 6.0 = ~ 24750 m kil... 


3 
8 4 
By arched connection h is increased to 70 .+ 85 = 95 em. The 
compression breadth b is the width of the girder = Dy = 0.35 mw. 
for stresses of a, = 50 kil/om® and o, = 1000 KiVon?, is 
ena 58 ‘% 5 AO 50 * 0.88 = xh SU il. 
1900 #6 -* 50: | Me 
de = 24.75 = 6 * 0.35% 0.38 * 50x 0.75 = S- 0.18 m tonne. 
Yet 2 rods of 2% mm are vent up and 2 rods of 27 mm are ins- : 
erted. To ensure the position of this. steel is provided i cor 
esponding number of stirrups., Bo that f 0 its gal ami | 
d. Galeulation of the Supports. — : f 
As Limitiag value of the allowaple coupressile stress on cons 
crete in piers is taken 24 kil/cu®. If a good wixture of conc— 
rete with a resistance. of 240 kilhjem® be assumed, thea. the» cone a 
PP bins stress in the concrete = Yio of dts resistence. i ce 
Loading on the support. i | PEM Vi si 


Pressure of main i P= 2 = dBeto = 21200 wit, i eats 
Pressure of side beam a debits SEE ad Fe ey a 


“ P= 9610" kil. Ae na : 
IZ a square pier with side a= 40 cM be assumed, thea withor 7 


ut tha reinforcement:- 1% \ ee: vee ae 
oy ear I 0 sag og. a 
: ae as 


According to formula -71 would be required: - HA 


~ f, 89610 ~ 24.0 -« 1600 be 
fo. = ei REN oe — ae 0.84 om? 
4 n Op5 ny XX 24.0 aa ’ ene ard pe ale 
Reinforcement of 4 rods of 18 um with. t, bene ph Rear nee 
Stree in 'pomoretesigithemem Mg a 
P © 80610 | ily) ee eat UN eae 
Ss aadirtenpapeennnbilinices 2S wae “hake 2 ‘Kitfost. Laas, ee A eee 
°o ett Bik. 40? + + “45x 708 | | Perak ile’ 
Stress in steel is Te =n dd), = 15 x 23. 2 843.0 kil/om®, ve ek 
Prom this ‘is i the distance between bands:- | 
Nye 15 : ; 
1 = 182.8 7 100.3 * 2 Be ay 
The distance between bands and side of pier are each Wokon MOR es aS aah ki 
he 1 | iM fet ba ; 
2t 40 cm. he RR 3 ERC 


Kote 1. Preferable in general ore smaller aietances betucen 


tands (20.t0o 60 cw). See Part I. 


¥e3 
Aye iArin 


oe cage i 
ees 


448 
&04. Base of Pier. 
For a height of pier of 3.0 m the base is loaded with:~ 


Load of girder on pier = P = 39610 kil. 
Weight of pier = about = _iei0- KEL, 
Pure ae oa = 40820 kid. 


For a base of pier 6 By Sqyarss the stress on the tamped Cc 


concrete footing ‘iso = = Sea #1418 %il/om?. 


fhe Telntorcement of the footing is computed as follons:~ 
P = 11.3 x 100 « 60 = 6780 kil. siaeal 
M = 6780 x 0.5 = 389 .m kil, ee 

Bor stresses of 0, = 24 kiV/cn* and 0, = 1000 Kien? and a 
‘compression breadth pb, = 0.40 4, is calculated: — 


A =~ a = 0.588 os = 17.1 cm: ob = 17 i ie 4 2.9 = 20. Oem,” 


{, = 0.187/38.9 & 6°70 40 = 2.13 en! o rods of 8 mm’ duanster. 
For practical reasons however is inserted a grating OF trey of 
80 to 100 kil/w® of the footing of. the pier, a 

Volume of footing = about:—-0. 608 0.1234 0 50? x 0 08 = - 0.088 oat, 

ay Weight of steel = 0 .0¢ 68 x 90 = 5.67 kil. ni a" es 

Inserted are» wmnibaeegs ° of 12 um, 5. 717 kil we etght for. a Lent tie 
of 65 om. tis. ee ae | | ss 
Aay calculation of the. pier with#peterelice to. buckling is uns 

neccessary according to. the Prussian Regulations, since, the. ge : 

height of pier is less than 18a, “This calculation as dura be. ei. 

required for 18 a = 18 x 0.40 = 7, g' ry tonnes. oi | nee $ s 
Galculation of volume for the. parpase of Hieiue 


For the calculation of the volume of the concrete a beara) he 3 a 
of 15 cm is assumed all. round for floors, . with one. of 35 cn ae ras 


tor peams. Fhe floors will be measured straight through over : 
beams and columns. The deals are computed as rectangular in 
section to the top of the floor, omitting. the addition for an 
arches. The columns are taken fron top of floor to top ot foot 
‘ing .or of floor. . . a ee eae ie 
for the centering the floor is again entirely measured , and 
for beams to top of floor, 1 since a considerable cutting ot 
lumber must be considered for the construction of the arches. 
Note ‘1.p.255. AVso- ‘emapsanyit Onky, to MOV. the. thickness ou 
the -fVoor. . 
The steel receives an addition of 15 to 25 .p.c. for bandeye 
iaps,and hooks, stirrups and bands, distributing rods and ‘Out 


ting for fipeet, with one of 20 to 30 p.c. for akeams, 


144 ae 
To avoid time-consuming computations, the calculated ro expres- 
sed in cm? may be taken as the weight in kil, which corresponds 
to an addition of about 27 p.c. One proceeds thus for floor s 
slabs, put can deduct there 10 p.c. from the final sum. * for. 
the piers must be resumed the addition of 27 \p.c., while for 
footings may be taken either 80 or 100 kil of steel per >of. 
concrete, or the weight of the steel reinforcement may be. com 
puted, 

Note 2Zepe2S5. If ane desires. to preceed with SATE | safety, 
then according. to whether : ‘AX cancerns 0 {recy -SUPpor Ved . slob 
Or one Fixed ot both sides» (continuous), Me Con. take 949.%0. 
Aet fg, nd 1.0 to -1¢ 52 for. the veow, or -1.0 7, for the. gor . 
ONG Lot Ff, For. the beam in. the end REkesx pane. 

The entire constructed floor area (thus not measured. frou 
interior to exterior of wall). amounis to 10.1 °x 7, Q- = 180. 72. 
u?. For 1 m*?,of this floor area are required: ~ | 

a. For floor slab,0.11 n° concrete, 0.96. me centering, and 
6,0 kil steel. MH Fi a a, 

b. For peam, 0.07 m3 concrete, 0. 82. n? rene’ 11.6 con ne 

As a total,:2 x 3.0 = 6.0 mg neakvot ‘piers: for i i lineal 
are required 0.16 m3 concrete, i. 60 nm? forms, D. 4 kil steel. 

(Note. The Table. ‘Of coupytations on Be 258 is. here “ 

“omitted for obvious - peasons).. | 
L579 Besides, there were constructed 2 pier: oo tiene ‘tay one. ny 4 
footing are necessary 0.06. m° concrete, 0.29 aprons, 8 kil ee, 


a 


steel. 
Estimate of Gost. i 
Tt is assumed, that the building site is vapowe! . ‘Ghlonetre 
distant from the railway station f. The cost of the building | 
materials delivered at the place for. use ‘is then: calculated as any 
follows, for example. | 3 | ae a | 
A. Portland cement, for 100 kil (2 scales} delivered at P 


‘ tue 
ape i 
bce 


: 4,40 Pay 
Pe cis veheratlh | i 7. 0.60 60 ee 
Lae Wet icost, ri eo mks seh 
Freight (2 mks. for 10 tonne car) adr ea mk. 
Unloading and hauling to building 2 OB | 
Lost, leakage and contingencies — : 0,04 
Q.12 


Total per 100 kils, say 3.95 marks. | | 
B. Sand up to 7 mm, for 10 tonne car= 6.5 m? delivered at F 


a Te Ot ee x a} ; ie 
abet an é sf i a i Were Rete fA i 
a . Bt us | 


145 | 
- = 13.30 marks. 


Freight, untoacing, nauling A unloading = 412.00 
Loss and contingencies, ¢ 1.70 
eee Total, 2900 marks. 
Thus for 1m? sand Teese = 4.15/u, Pe 
Cc. Gravel from 7 to 25 ma, for -10 tonnes car, 6.0 w?, deliv- 
ered at Station F. ie 18.00 marks. | 
Freight, unloading. twice, hauling, 12.00 
Loss and contingéssies, | Vo Naat Woe PeeOUse cae) 
Total hee eo: : 
Thus per m of grate] = 2. 5.35 marks. Pa eres oa, 
d. Steel for beams and ‘floor Slab. oy, ; ‘Bean, “Blab. 2 
° 100 kil at the works = a as OOO, ca 
Preight to station F= Py eae er ites ot ve 
Unloading and hauling to building | PW OsaG ay Os 16 
, Unloading there = ) tea: Gon” aes 
Extra price = RO A anaes Cie RET 
Bending = RR CO cr Or BRUM Me Cay 
Placing and wiring = OE WRB aR On Gh A arnt 
Por 100 kil.io ys Totalegt ke ts 228g) Peake : 
Thus per kil = | | ro Ae 8 Os a 
‘axing propersiens.(nachine) for. the ‘concrete will be as 
Tollows: -- 7 cn eet Ne a Fi 
‘300 kil cement .+ 500. Mites: sand + 600 B00 ‘litres. ‘eres 
Gost .per n? tamped concrete then amounts: nea, es | nad hs 
300 kil cement at 3.95 AeA ‘nl = Mr il. 85 mks. 
500 Litres sand at 4.45 #ks/m? = = | ee NT idg i oe a Sy 
800 litres gravel at 5.35 nks/ti? = } oe Vise A 
‘  Potal per i? = 18021 marks. 


For 1 area = O«di 1? concrete at 18.2 aks 3 
Wages for mixing, placing and tamping, 0.96 Be = rent 
Making and ‘removing centering, 0.96 mes a peta 

lioving and placing: ‘steel, 6 kil at 0. AQ see 4.4 14 


i. Unit cost of floor slab. Oy ee Pa ah) 


Total per n¢.= PE hd Fae 5s 235 Me hi 


‘Ze Unit ‘cost of. beans. ar 


For 1 ne horizontal area = Be 06 #3 concrete at. 46. aL ae 


iages at 10.0 } aN 
Forms, 0.52 i? at 2.20 = TENA Tieg rt Ra 


Steel, 11.6 kil ‘at. 0.13 ye 


146 | 
Steel, 11.6 kil at 0.18 marks = | 2.03 
‘Total per 1 Wego 
3. Unit cost of piers and footings. 


For ‘%.m kin. of pier 0.16 u? conerete at:18.2 = 
Wages at 12.00 = \ asi 
forms, 1.60 m¢ at 3.0 marks = _ 4.80 
“Steel, 7.1 kil at 0.16 marks = te hges ee 
Fotal -per. Al lin. of -pier = 10.92 marks. 
Forol pier footing, 0. 06 mn? concrete at 1862 = ay 
Wages = 8.0 rela =) : i 4.57 
Forms, 0.29 m* at-4.00 = ee i 0629 
Steel, 5.8 kil at. (0.18 Mark = 5) 7 ake Rey ath A Se 
thi fotal for footing = ee “2.50 ge 
Bidding Prices. f ec OG : ea 
4. Floor, including beans, Unit cost 5.3) 4.4.93 = 10428 
Overhead cost and profit, assumed at 25 .p.c. = 2.59? 3 
otal in marks per m4 = aa no aly Mage 
2. Piers including footing. ie hae 4 Ose aces 
Unit cost per pier, perm lin = ae eae 10.92 ae aoe 
Unit cost of footing per & din. = 3700 me ; Pale 0.97 Sig at 
: D sae yf BRABG, PUES CR, 
Qver head cost & Profits $25 ipsc. =e ra Ca 
Total per m Lin. cag has ie \ _ cassie ; 
Form of Bid. i pe Amount. ae axe 
NO. Description of Work. ei aes Unite, |). Total. Sie ey 
1. 181 04 reinforced ‘concrete floor with beams, ete 
constructed according to drawings, caleu- 
lated for a live load of 500 \kil# 50. pec. Be 
addition for shock, including the necess- 
ary forms and framework, but not plaster~ 
‘ing underside. Top surface to be horizon 
tal and smoothed. 3 Se 
181i n+ actual area, without deduction of op- | 
ening for ladder of i m¢, eng 2354. Om 


4 Reinforced ‘concrete piers Girsquare section, — 
calculated for. the loads mentioned in var- 
agraph 1, including footing and all necessary 
forms and framework, ‘but not plastering 
the external surfaces. . 

6.0 m Lin. Measured from top to top of Lived, 


44693 marks. 


toe, 


ay ie 


ROR 


Se 


173 


per m lineal = 14.9 89.40 
Total 2434030 m. 

Goating visible surfaces mentioned under 

Nos. 1 and 2 once with cement milk and 

twice with limewash, per 1 m* at O«25 

14 at 0.25 mark = 60.75 

Cement plastering 2 cm thick, mixed-1°: 3, 

laia on floor mentioned in No. i, rounded 

to 5 cm high at side walls, 114 at 1.40, 

i+ at 1.40 = iy: 22 22Q 


Total 2927225 Me 


te 


(AC [4G 


Designation. Concrete. 


Quantity. | m? 


1. Faoor panels 


Panel a 2X17 .90%2.55%0012 = | 10.955 
Panel b 2-* 17.90 x 2.50 x 0.10 = 8.950 
| Total 496905. 
2. Beams. 4 ei aa | 8 Wes ae RS 
Main girder 2 Ax Be25 x 0030 x 0.70 at eae 40410 
Side beam I.a ‘4 -M4OLI5 * O685-x OLE5 Mic a eres 
Side beam T’a (i i (2K B15 0685 * 0045 = 46384. 
Side beam I b_ 2 *)6.00 *'0525°% 0.45 = 7 >.) 46850 
Side beam 7b 8 186600 % 0625 % 0265 = i OOF: 
| bUahaee otal - 5 aaron: 
3. Piers . 2% 3,00 x 0.40 * 0.40 = 0.960 
A, Footings : 2% 0.60 * 0.60 x 0-12 a coche 
‘a | Bx 0.50% 0.50 «0. 08 =) Mie: ok 
5. Plastering at Gedling surface : 


Surfaces of girders | 
‘Surfaces of beams 
Surfaces of piers | 


sty ae 


6. Cement plastering 


Zt 


Ae 


She 


AW A.t 


Ba 


PA 
BOGE 


Gentering & Forms. né Steel. kil. 
Quantity. m+, Quantity. ‘kil. 
4 4.90 (2 °* 0.70 + 0.30) = 33.32 .4.* 5425 «34.40 = 922.4 
4 ‘* 5.80 (2 “*% 0.45 at 0.25) oes 26.66 4 as 6015 as 29.08 3 7154 
2:% 6.00 (1615) = 43.80  2-*% 6.00 x .16.62 = 199.5 
'1°-%,6.00 '€1si5): = 6.90 1 -x 6.00:* 16.62 = 99.7 
| Total 94.04 2094.7 
2 -* 3.00 (4% 0.40) = $.60 2:x:3.00€ 7.08 = 42.45 
2% 4% 0.60 -* 0412 = 0.58 2: 10-x 0.65 x 0.888 = 21.6 
9. * Ly 280 = | 472050 
3 2960 O995 22.5 36.56 
3080 x 17.60 = 172650 
3° 49,68 x) 0095 xi 36.96 
Z &, 9.80 * 0.60 «Qa 23.254 
2 :X3)'*2 1,605 __ 9-60 
Total 242.60 
17.60 « 9.80 = 172.48 


NG 
apt ih 


Vode 


150 
ANDEX TO VOLUWNE II. 


Viré=-tile walls 


Preface ---7>---- ee ee een ee ee ee page @ 
Handbuch der Hisenbetonbau, Contents- : NB a EI We sr 
Section 1. Employment in Building Gonstruction fy aS e 
A. Intermediate. floors and céilings- ------ PM 6 
Frotection from heat and cold rah oe kok tc es Pgh ce ee ae ie! Lays 7 
Thickness of walls ------- ip i a a e #| 
Floor coverings - - - - BF ee ee ae age re ane woe 
Plastered setMiuged/=/40— - a= es Pe ee a 
Cénsbrucbion ‘of.floors~\— - =5 4-2) 4a s were, o 
Monier floors - - - - a — ae oe el 
Continuous floors ee ms ee eee 
Koenen’s floors ---------- - ~ --- Nh 2 Soe Os 
Pumice concrete floors- Pa as te -- my ie a ae ai ete 
Reinforced brick floors -'- See: ge) ane - a - Z a 16 
Bégert’s ‘floors — - <j- + = - Gain nin a he abe 
Hollow slab floors- - - - - - - --- ~-Se oo e- a Yi 
Cellular floors - - - ~ Ne me mt) Jee _ a ~~ - 1g 7 
Lelnan floors =o - a gt Pe te ies ee 
Hollow bloek floors --~----+----------- 2 
Reed tubular floors - - - - - - a silat alitetiadiced titatied tea 
Wrissenberg floors - = - - - - i iene che ee 
Herbst sloors <<) 5 gs See rie a ei ee ae 
Factory made beams- -~--cc- -- - - - --- -- -~-- 24 “ 
Visintini girders -------+-----7------2 
Ribbed floors - --- TSB Toes - w -- 2 -- bi o--- - oe 26 “ 
Coffered ceilings Ra sal tg < 8 - ---- --- ” - - 28 
ixpanded metal reinforcement- - -- a MWe. soe --- --- 29 
Kahn bar reinzorcement- - -- ---------~+---~30 
Pohimann ffoors <j ~~ - es ~ as ee ae 
Glass and concrete ceilings - Pc Saeed at ile ---- - - 33 
Bb. Supports and Piers- ---- +e ee ----- - - 34 
Séetions |. s~ ties Thr SC ee a ee ee ate 
Reinforcements \G~ <-> <5 Tale TR Gee eae 
Spirally banded <= tor t,t St ty Ge aay, 
Pier:footings — — Go = > $e ee ee 
C. Division and. external walls - Wiehe -- rat ces Sek 
Reinforcemént —- - ig Te avert ee + i ee hee eee - near Ne. - 37 
Protection ‘from :heat and :COLG ss) my ee ess he, ce aes 
Yonier walls- ----------------+----- 3 


ee 
Rs 


De eh Soe ee 

‘Ye ' 

BoB NS aah ee 
es 


Sy 
Rien} oe 


et gat, 
ess a 


i 


beam roois- or Gc ete. oetag edicts es te 
Live loads on roofs wee = 


Wire-tile walls ---------- te Tae Sree mae  ere a a -- 
Expanded metal walls- se be aN aa AN Ae cE kat yaa, Cam 
Reinforced brick walls- OT END AEE HN Ps es te 
Hollow block walls- - - - - pe alin NAR. aie ey Moa a 
D,: Stairedys = - 472) 5. ae gis ate 2 IRE EN R p akt UE A 
Advantages of concrete- lg gees lage agaebanmat | dae Pane us 
Breely supported staireys ~ eo ee eS 6 eer 
Landings- ------------ A: ieee te a cae gd a 
Stairs partly fixed - - . t a - i eee oe wor Siecle te 
Reinforced concrete strings - Oi clay ae re OU slp ok 
Stairs with warped surfaces - ike! Gee. BoM tae iets 
Berlin rules for stairs - - ~- Pe Ma Ae YA IY 
ioulds for steps- - - - - - - - pian, 5 lm SSG Meh 
yonier stairs -- -------=------~---+--- 
i. Corbel and console structures - - . ee ea he 
Babeontes ~/+ — Jie lp 8 = - ciel Se or 
Bay windows ------------------- Ste et, 
Galleries in halis- -~------ cig na 1 SOME eSB a 
Supports for crane tracks ---- - --- -- -~----- 
F. Other applications- - - - - += -- >= ORAS TS y 
Advantages of concrete in houses-~ ---- +--+ AMG 
Special forms of floors - - - - --- a chs: =A RC 
Door and window lintels - ree - fo oe _ a - - 
Corniccae nt ct Wee ee ee ce ne 
Chimney flues - --------------------- 
> Bxpansion :joints->- ie ee ei hoe oe 
Frame and panel walls - - - a --- mate © saghan tue ini oat (ath plas 
Power and lighting lines- --- - - ssa et tee cee 
Driveways and (bridges: = - - = s4)> - = sei = =pe a -- 
Floors of offices ‘and shops - ~---2--+-—--4-- 
Hardening surfaces- 2 eee -~--------- --- 
G. Roofs and halls - - ------------+--- 
Covering and “Insulauton je eS ae ee ee en cree 
Wood :camenh, gir. Sigiie ri xm ie ees) See eer ne a 
Rubsroids. Foe = gees Gabe Soe ee ae a uit 
Slate le < Pee is he rete a ee ees 
Insulation- -- --+------5- + -- t-te 
Steel framework - - - ~ - - - - 8+ cin RS See ae 


Bip, ROGLE ort min Sele. rst a) eae ae ee ae error eer ae 
Bactory tects <<) ~ pm oc ie ar ee ee ee 
Sawtooth roofs- - - - - - ~~ i. : tl ee ie at us Sree a ea 
Rrajecting Pooteg.- ai Tere ps ue gee oe ee OF 
frussed ‘roofs’ = + —- sm = se He eee ws -- ab ers a 
Wansard ‘roofs sine aes me ee Sie i el a 68 
Halls witn frame beams and arches - MEY SG) ae! gE AO 69 
FPVSmes “WA GD: GG UA Bir me es eee mm et ae oe rae a ay 2 
Frames with three posts - - “ae, “ Me” Oe a OG ne aes hy 
FRAMES) CEMSR SE Sm ee te ee nee ae Sle A eee ee ~72 
Arched trusses~- - - - = --- a - Re iY de SUBSITE ~T4 
Vaulias gtd’ ie hcigin <0 — cae ei re 
aie ones he bgt Oo a a i 
Section ‘The Foundations and walls- == pe ig 79. 
A. Foundations - ---------- Re ee ess 
Concrete slab over site ae Te -|- - F et ee a BLS 
Machinery; foundations |= -.- = - - - Sieg: n= mint 4 ee 
Vaults and stiff frames - - ----- - “ticle co ee a eet am 
Piles made in factories Pe ee ce ot -- - - he rs Fy pega 83 AR 
Advantages<"—) == =" a eal neta - lens -- ig Oe 83. | 
Wanufactoure and reinforcenent- - ------- = Pirie iy Bde 
Formula ior bearing a '< e ae oa eee - r --»- - “yt ape 
Piles wade in place ----------+-------= 86" 
Strauss sysbene eT = te So0 ce : ---- 87 
Simplex system- - - - - - pe ee ee eer 
Orane rails on piles- ------------------ 8 
Sunken wells- -- --*4----- +--+ 05774 -- 8 
Be Watertight cellars- cr. oki he tga sae -- i B89 
Presection' OL WALES ri! — Fairer ms ee ae --- 92 
C. Walls subject to pressure - - ~ -~ ee ~---- 92 
Bnclosing walls ---->-- 7-7-5 St ttc 9 
farget walls- --------- 7-7 c rrr tt ttt 
Retaining walls ~"9- ie = clog oo ee Ae See oe 
Angle retahbing walls — 2-5 = - Be in eg an eee 
Reinforcement - aim eS te ee ee 
Sheet (pLEinee a a ee. Ta ae aes = eee ee 
Shore and ‘quay walls- celtiat aviobion tate hon Re COMO e han 
Section Ili. Pipes and reservoirs- Titorlerti, edhe: each oe 
A. Pipes, ‘channels and culvyertss-)-- 4 sia ss = Bee 
Advantages of CONCTCEC> ye aie eee eae oY 


ah 


ery 


AY 
3 52) 


eae 


Picea: 


rae 
ae ee 


Resistance to acids and gases ------=- GRE RR U8 SES ook 100 
Bi Reservoirs) = & <a Ae Se ee ea er 
Makins them watertisht= = sie Ss See 101 
Réectassular’ <0 si be a me ee ee ean ee ee ee 102 
Covering reas Sr tral: Mtge geet inks she ae, cia i ig ee eS wy x 102. 
Qiroular- a seek GR et oe a = ee 
Hemispherical -- ---------- bi a 
Gasometer tanks -- -----------7-=--~- = - 10d 
Elevated water tanks- --------------- a oa 
Swimming pools; ~ =~ --- - ae a tag | 
Gurbine chambers = - -- +--+ - 5-5-7 oo 7 > 7408 
Bins and silos- -)- -----7--75-55 7774 eee 
Elevator bins - 3 ~~ --~-=-- qo - 4-4-7109, 
Bin bottoms ---------7 eee c ct etre 110 
Section iv. Hydraulic enginsering- = Rey pick ce ee a7 
Dans< So) Pate ero ae See ce - pel ating: + iatataae et crck itt am steer Aid 
Bank retaining walls- - - ------------ Le eke 
Piers @ = + Siti - Bi ee Se ee, 
Quays --- - - ee oe ree - ~----+---- Ba Ce per ne 
Pontoons and ships- adalat ee Seve a) oa 
Section V. Other applications --------- — bt] 
A. Agricultural structures ¥ aa -- -= > fe ae Eee oe - - 115 Bae « 
-B. Street and Railway construction | -e-- eet me MABE ae 
Hes--~---+---9---- 1B Se ee ee, ne 
Telegraph POLES — =p etl e = - - ~--+------ = thd: , 
CREBE oe ak eee er Conneae ---- - oat +h ---- ite tae 
Gs Buildings for sports and sclence- - - - --- - - ~ 118 ate 
Bicycle course- --- -=--=- ses - 5 - - wae en 
Apvifsaial Biliscie oa a ee = laste eatin ts wee 1G 
D. Ghimeys- -—4 -----~45-G 57+ geo oe eae 
advantages- - ------- cect ttt 
Reinforcement — aR wit ee So - Se aise --- ~ 120 
. Mining structures - - - ae ------ -- se ~ - 120. 
agnctie VI. Calculation and construction rin Ara tate - 4121. 
4. Floor reinforced crosswise ---- - ent etek ~-~- 121 
2.) Window 2intele = - om ei Me ee ee - - 122 
35. Pier? TOOting ss eit on ae _ = otters ~ 122 | 
4, Foundation: = ste is so SRS ot ee ee a Pa 
5. Step (OP iStalrs ie es or ae ---- - = 123. 
6. Stairs with string -----=----- 74555 - = 124. 
7 : 


Sawtooth shéd -----=--- +--+ ---- +--+ - 125 
Arched :roof- ----------+--+--+---+--+-+--.- 128 
Circular tankK- ------=-----+----- - - -130 
Water: towern\~ ya's sonnet eee ae ee ee 
Retaining wall ---------------- = - -435 
Hall with gallery- -------- oa ~136 
Section VII. Designing shop floor- By ahem eg yy tit 137 
Bloor slab 5 ne ee ele oe ees 
Side DOORS s SOT es Tal yee ee een mn 
Girder - - - ble twin. comme earn eat Manner om a ri Tice cadet ae ~141 
PlerSe---- - —- - ee tee ee eee ee ee 142 
Volume Gnd @O8ty a elm: Sumo Caen ai eas ae Oc ae 
Estimate of cost -+>--=->-- fe - re eee = 144 
cerns es Tt ee ee a ee 
Table On. Pp. 258- = Sra, oy Um Sa MM tee aller hs aay, ky -146 


Iidek to Volume II ------~---------- -i49 


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